diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4a00e9814..f097b3f76 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -38,43 +38,7 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - desc: gcc6/C++14 llvm9 py2.7 exr2.4 oiio2.3 sse2
-            nametag: linux-vfx2020
-            runner: ubuntu-latest
-            container: aswftesting/ci-osl:2019-clang9
-            vfxyear: 2019
-            cxx_std: 14
-            openexr_ver: v2.4.3
-            openimageio_ver: v2.4.13.0
-            python_ver: 2.7
-            pybind11_ver: v2.4.2
-            setenvs: export CMAKE_VERSION=3.15.5
-          - desc: clang9/C++14 llvm9 oiio-release avx2 exr2.4 py2.7
-            nametag: linux-clang9-llvm9
-            runner: ubuntu-20.04
-            container: aswftesting/ci-osl:2019-clang9
-            vfxyear: 2019
-            cc_compiler: clang
-            cxx_compiler: clang++
-            cxx_std: 14
-            openexr_ver: v2.4.3
-            openimageio_ver: release
-            python_ver: 2.7
-            # pybind11_ver: v2.9.0
-            simd: avx
-            setenvs: export CMAKE_VERSION=3.15.5
-          - desc: gcc6/C++14 llvm10 py3.7 exr2.4 oiio2.2 sse4
-            nametag: linux-vfx2020
-            runner: ubuntu-latest
-            container: aswftesting/ci-osl:2020
-            vfxyear: 2020
-            cxx_std: 14
-            openimageio_ver: v2.4.13.0
-            python_ver: 3.7
-            pybind11_ver: v2.5.0
-            simd: sse4.2
-            setenvs: export CONAN_LLVM_VERSION=10.0.1
-          - desc: gcc9/C++17 llvm11 py3.7 exr2.5 oiio2.3 sse2 batch-b4sse2
+          - desc: gcc9/C++17 llvm11 py3.7 exr2.5 oiio2.3 sse4 batch-b8avx2
             nametag: linux-vfx2021
             runner: ubuntu-latest
             container: aswftesting/ci-osl:2021-clang11
@@ -83,9 +47,9 @@ jobs:
             openimageio_ver: v2.4.13.0
             python_ver: 3.7
             pybind11_ver: v2.7.0
-            simd: sse2
-            batched: b4_SSE2
-          - desc: gcc9/C++17 llvm11 py3.7 exr2.5 oiio2.3 avx2 batch-b8avx2
+            simd: sse4.2
+            batched: b8_AVX2_noFMA
+          - desc: gcc9/C++17 llvm11 py3.7 exr2.5 oiio2.3 sse2 batch-b4sse2
             nametag: linux-vfx2021
             runner: ubuntu-latest
             container: aswftesting/ci-osl:2021-clang11
@@ -94,8 +58,8 @@ jobs:
             openimageio_ver: v2.4.13.0
             python_ver: 3.7
             pybind11_ver: v2.7.0
-            simd: avx2,f16c
-            batched: b8_AVX2_noFMA
+            simd: sse2
+            batched: b4_SSE2
           - desc: gcc9/C++17 llvm13 py3.9 exr3.1 oiio-rel avx2
             nametag: linux-vfx2022
             runner: ubuntu-latest
@@ -158,6 +122,7 @@ jobs:
             simd: avx2,f16c
             batched: b8_AVX2_noFMA
             setenvs: export OSL_CMAKE_FLAGS="-DSTOP_ON_WARNING=OFF" USE_OPENVDB=0
+                            OPENCOLORIO_VERSION=v2.3.2 OPENCOLORIO_CXX=g++
           - desc: gcc11/C++17 llvm15 py3.10 exr3.1 oiio-rel avx2
             nametag: linux-vfx2023
             runner: ubuntu-latest
@@ -182,15 +147,15 @@ jobs:
             skip_tests: 1
             setenvs: export OSL_CMAKE_FLAGS="-DOSL_USE_OPTIX=1" OPTIX_VERSION=7.0
                             OPENIMAGEIO_CMAKE_FLAGS=-DBUILD_FMT_VERSION=9.1.0
-          - desc: oldest everything gcc6/C++14 llvm9 py2.7 oiio2.3 no-simd exr2.4
+          - desc: oldest everything gcc9/C++17 llvm9 py3.7 oiio2.3 no-simd exr2.4
             nametag: linux-oldest
             runner: ubuntu-latest
-            container: aswftesting/ci-osl:2019-clang9
-            vfxyear: 2019
-            cxx_std: 14
+            container: aswftesting/ci-osl:2021-clang11
+            vfxyear: 2021
+            cxx_std: 17
             openexr_ver: v2.4.3
             openimageio_ver: v2.4.13.0
-            python_ver: 2.7
+            python_ver: 3.7
             pybind11_ver: v2.7.0
             simd: 0
             setenvs: export PUGIXML_VERSION=v1.8
@@ -276,6 +241,8 @@ jobs:
       USE_BATCHED: ${{matrix.batched}}
       USE_SIMD: ${{matrix.simd}}
       ABI_CHECK: ${{matrix.abi_check}}
+      ACTIONS_RUNNER_FORCE_ACTIONS_NODE_VERSION: node16
+      ACTIONS_ALLOW_USE_UNSECURE_NODE_VERSION: true
     steps:
       # We would like to use harden-runner, but it flags too many false
       # positives, every time we download a dependency. We should use it only
@@ -353,11 +320,11 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - desc: Debug gcc7/C++14 llvm9 py2.7 oiio2.3 exr2.4 sse4 exr2.4
+          - desc: Debug gcc7/C++17 llvm9 py3.7 oiio2.3 exr2.4 sse4 exr2.4
             nametag: linux-debug-gcc7-llvm9
             runner: ubuntu-20.04
-            cxx_compiler: g++-7
-            cxx_std: 14
+            cxx_compiler: g++-9
+            cxx_std: 17
             openexr_ver: v2.4.3
             openimageio_ver: v2.4.13.0
             pybind11_ver: v2.6.2
diff --git a/CHANGES.md b/CHANGES.md
index a2c2b87e7..3eaa51601 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -6,42 +6,158 @@ Release 1.14 -- in progress (compared to 1.13)
 ### New minimum dependencies and compatibility changes:
 
 * Note: it is likely that by the time it is released, OSL 1.14 will require
-  Imath >= 3.1.
+  Imath >= 3.1, Python >= 3.7, C++ >= 17, gcc >= 9.3.
 
 
-### OSL Language and oslc compiler (for shader writers):
+### OSL Language, standard library, and oslc compiler (for shader writers):
+  - Fix the subsurface_bssrdf parameters to conform to MaterialX. [#1823](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1823) (by Christopher Kulla) (1.14.1.0)
 
 
 ### ⛰️  API changes and new ShadingSystem features (for renderer writers):
+* The big switch to `ustringhash`: To better accommodate GPU execution, and to
+  make the code and techniques less divergent between CPU and GPU code paths,
+  we have changed the runtime representation of strings from `ustring` to
+  `ustringhash` -- which is still a 64 bit token, but rather than the address
+  of the unique characters, which may change from run to run and harm the
+  OptiX/CUDA PTX cache performance, it is the deterministic hash of the
+  characters. Thus, not just the runtime, but all of the interfaces of
+  RendererServices and other APIs that the renderers use to set up and
+  communicate with the ShadingSystem, now have been changed to expect
+  ustringhash instead of ustring.
+  [#1732](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1732) (by Steena Monteiro) (1.14.0.0)
+* Add API for building interpolated getter free functions.
+  [#1765](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1765) (by Thibault Vergne) (1.14.0.0)
+* Switch `shade_image()` to use current OIIO::paropt [#1843](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1843) (1.14.1.1)
 
 
 ### 🚀  SIMD batched shading mode
+  - *batched*: Codegen bug for compref with varying index [#1776](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1776) (by Alex Wells) (1.14.1.0)
 
 
 ### 🚀  OptiX GPU rendering
+  - Fix NVPTX TargetMachine leak, etc. [#1763](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1763) (by Tim Grant) (1.14.0.0)
+  - Fix GPU interpolated param initialization [#1791](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1791) (by Chris Hellmuth) (1.14.1.0)
+  - Add `lazytrace` ShadingSystem option to avoid combinatoric optixTrace
+    inlining: when enabled, run layers with trace ops unconditionally at the
+    start of shader evaluation. This costs some potential performance in cases
+    where the trace layer would never be evaluated, but removes all the
+    compilation penalties that the inlining was presenting.
+    [#1815](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1815) (by Chris Hellmuth) (1.14.1.0)
 
 
 ### 🐛/🔧  Internals: fixes, improvements, and developer concerns
+  - Mute partio error prints [#1774](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1774) (by olegul) (1.14.1.0)
+  - calculatenormal needs to use the fliphandedness global [#1783](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1783) (by sfriedmapixar) (1.14.1.0)
+  - Print closure missing error message at compile time instead of run time.  [#1781](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1781) (by sfriedmapixar) (1.14.1.0)
+  - Make isconnected() work with downstream renderer "connections." [#1782](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1782) (by sfriedmapixar) (1.14.1.0)
+  - *int*: Change OSL_CONSTEXPR14 to constexpr [#1805](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1805) (1.14.1.0)
+  - Remove unnecessary ustring lookup [#1824](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1824) (by Chris Hellmuth) (1.14.1.0)
+  - Make backfacing shadeop indicate backfacing shader-global is needed [#1827](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1827) (by sfriedmapixar) (1.14.1.0)
+  - Reparameter string needed to be ustringhash [#1841](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1841) (by Chris Hellmuth) (1.14.1.0)
+  - Some modernization of osl.imageio [#1840](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1840) (1.14.1.1)
 
 
 ### 🏗  Build/test/CI and platform ports
 
 * CMake build system and scripts:
+  - *build*: Add options to use static Cuda libraries (controlled by
+    CMake variable `CUDA_PREFER_STATIC_LIBS`) [#1772](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1772) (1.14.1.0)
+  - *build*: Remove a lot of old SPI build cruft [#1778](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1778) (1.14.1.0)
+  - Simplify oslquery library include and link needs [#1787](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1787) (1.14.1.0)
+  - Propagate cpp version: when building against an OIIO that needs C++17,
+    OSL will need to be build with C++17, too. [#1797](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1797) (1.14.1.0)
+  - Eliminate boost as a dependency: [#1802](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1802) (by Christopher Kulla) (1.14.1.0) [#1808](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1808) (by Christopher Kulla) (1.14.1.0)
+  - Default to C++17 mode (but for now, C++14 is still supported by
+    setting `CMAKE_CXX_STANDARD`). [#1818](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1818) (1.14.1.0)
 * Dependency version support:
+  - Support for LLVM 18. [#1773](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1773) (by مهدي شينون (Mehdi Chinoune)) (1.14.1.0)
+    [#1803](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1803) (1.14.1.0)
+  - LLVM 18 compat issue - include libclangAPINotes [#1812](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1812) (1.14.1.1)
+  - Various fixes to deal with deprecations in the development branch and
+    upcoming 3.0 release of OpenImageIO:
+    [#1788](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1788) (1.14.1.0), [#1806](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1806) (1.14.1.0), [#1834](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1834) (1.14.1.0), [#1838](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1838) (1.14.1.0), [#1842](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1842) (1.14.1.1), [#1844](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1844) (1.14.1.1)
+  - *Use new OIIO ustringhash decode methods when available [#1792](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1792) (by Chris Hellmuth) (1.14.1.0)
 * Testing and Continuous integration (CI) systems:
+  - *(testrender)*: Fix testrender GPU regression with bad destruction order [#1814](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1814) (1.14.1.0)
+  - *(testrender)*: Implement new Oren-Nayar model from OpenPBR [#1817](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1817) (by Christopher Kulla) (1.14.1.0)
+  - *(testrender)*: Implement OpenPBR's sheen BRDF [#1819](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1819) (by Christopher Kulla) (1.14.1.0)
+  - *tests*: Update ref output for OptiX execution order variance [#1816](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1816) (1.14.1.0)
+  - *ci*: Test against LLVM 17 [#1760](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1760) (1.14.0.0)
+  - *ci*: Increase timeout for slow MacOS-13 runner [#1775](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1775) (1.14.1.0)
+  - *ci*: Fix broken Macos-13 CI [#1780](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1780) (1.14.1.0)
+  - *ci*: Allow triggering CI workflow from web [#1779](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1779) (1.14.1.0)
+  - *ci*: Lock down to OIIO 2.5 for icc tests [#1799](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1799) (1.14.1.0)
+  - *ci*: Print commit hash of locally built dependencies [#1798](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1798) (1.14.1.0)
+  - *ci*: Suppress leak sanitizer warnings about internals of robin_hash [#1807](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1807) (1.14.1.0)
+  - *ci*: Mods to CI to deal with OIIO master raising dependency mins [#1833](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1833) (1.14.1.0)
+  - *ci*: Fix GHA CI after they upgraded nodejs [#1837](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1837) (1.14.1.0)
+  - *ci*: Deal with CentOS 7 EOL and disappearance of yum mirrors [#1839](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1839) (1.14.1.0)
 * Platform support:
+  - *Mac ARM*: Test with Mac ARM runner [#1770](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1770) (1.14.1.0)
+  - *Mac ARM*: Make finding bison work better on Apple Silicon Macs + homebrew
+    [#1822](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1822) (1.14.1.1)
 
 ### 📚  Documentation
-
+  - Fix links to RTD docs from github landing page [#1768](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1768) (1.14.0.0)
+  - Clarify behavior of `round()`: OSL uses "round away from zero" policy for
+    input values exactly half way between two integers, matching C/C++
+    standard round(). But we were not clear about it in the docs.
+    [#1767](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1767) (1.14.1.0)
+  - More detail about supported platforms in INSTALL.md [#1796](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1796) (1.14.1.0)
+  - Fix outdated or wrong repo URLs [#1811](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1811) (1.14.1.0)
+  - Fixes to documentation of new oren_nayar_diffuse_bsdf parameters [#1820](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1820) (1.14.1.0)
 
 ### 🏢  Project Administration
+  - Account for duplicate emails in the .mailmap [#1759](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1759) (1.14.0.0)
+  - Releases trigger automatic announcements to the Slack channel.
+    [#1766](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1766) [#1777](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1777) (by John Mertic) (1.14.1.0)
+  - Raise our code formatting standard to clang-format 17 [#1761](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1761) (1.14.0.0)
 
 
 
 
 
-Release 1.13 -- beta 1: December 20, 2023 (compared to 1.12)
--------------------------------------------------------------
+Release 1.13.10.0 -- 1 June 2024 (compared to 1.13.9.0)
+--------------------------------------------------------
+  - *testrender*: Implement new Oren-Nayar model from OpenPBR [#1817](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1817) (by Christopher Kulla)
+  - *docs*: Fix outdated or wrong repo URLs [#1811](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1811)
+
+
+Release 1.13.9.0 -- 1 May 2024 (compared to 1.13.8.0)
+--------------------------------------------------------
+  - *deps*: Support for LLVM-18 [#1773](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1773) (by مهدي شينون (Mehdi Chinoune) [#1803](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1803) (by Larry Gritz)
+  - *fix*: Make isconnected() work with downstream renderer "connections." [#1782](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1782) (by sfriedmapixar)
+  - *cleanup*: Change OSL_CONSTEXPR14 to constexpr [#1805](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1805)
+  - *internals build*: Fix ifdef typo [#1804](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1804)
+  - *build*: Propagate cpp version [#1797](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1797)
+  - *build*: Print commit hash of locally built dependencies [#1798](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1798)
+  - *ci*: Lock down to OIIO 2.5 for icc tests [#1799](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1799)
+  - *ci*: Suppress leak sanitizer warnings about internals of robin_hash [#1807](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1807)
+  - *docs*: More detail about supported platforms in INSTALL.md [#1796](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1796)
+
+
+Release 1.13.8.0 -- 1 Apr 2024 (compared to 1.13.7.0)
+--------------------------------------------------------
+* *fix(batched)*: Codegen bug for compref with varying index for batched shading [#1776](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1776) (by Alex Wells)
+* *fix*: Calculatenormal needs fliphandedness [#1783](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1783) (by sfriedmapixar)
+* *fix*: Print closure missing error message at compile time instead of run time.  [#1781](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1781) (by sfriedmapixar)
+* *int*: Change long-deprecated OIIO macro to new one [#1788](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1788)
+* *ci*: Fix broken Macos-13 CI [#1780](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1780)
+
+Release 1.13.7.0 -- 1 Mar 2024 (compared to 1.13.6.1)
+--------------------------------------------------------
+* *fix*: Mute partio error prints [#1774](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1774) (by olegul)
+* *ci*: Test with Mac ARM runner [#1770](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1770)
+* *docs*: Fix links to RTD docs from github landing page [#1768](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1768)
+* *admin*: Switch release announcement workflow to jmertic's awesome action [#1766](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1766)
+
+<br>
+
+
+Release 1.13 -- Feb 1, 2024 (compared to 1.12)
+===============================================
+- beta 1: December 20, 2023
+- release v1.13.6.1: Feb 1, 2024
 
 ### New minimum dependencies and compatibility changes:
 
@@ -130,6 +246,7 @@ Release 1.13 -- beta 1: December 20, 2023 (compared to 1.12)
 * OptiX PTX pipeline overhaul [#1680](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1680) (by Tim Grant) (1.13.5.0)
 * Perf: Don't insert redundant run layer calls inside a basic block
   [#1665](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1665) [#1669](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1669) [#1672](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1672) (by Chris Hellmuth) (1.13.4.0)
+* Fix NVPTX TargetMachine leak, etc. [#1763](https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/1763) (by Tim Grant)
 
 ### 🐛/🔧  Internals: fixes, improvements, and developer concerns
 
@@ -225,6 +342,7 @@ Release 1.13 -- beta 1: December 20, 2023 (compared to 1.12)
     * For clarity, use the term 'runner' instead of 'os' [#1743](https://github.com/AcademySoftwareFoundation/OpenShadingLangauge/pull/1743)
     * Test ABI compliance [#1748](https://github.com/AcademySoftwareFoundation/OpenShadingLangauge/pull/1748)
     * Fix tests passing when test commands fail [#1733](https://github.com/AcademySoftwareFoundation/OpenShadingLangauge/pull/1733) (by Brecht Van Lommel)
+    * *ci*: Test against LLVM 17 [#1760](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1760)
 * Platform support:
     * Include `immintrin.h` only when needed. #1605 (1.13.1.0)
     * Changed snprintf formatting to satisfy some compilers.
@@ -250,6 +368,7 @@ Release 1.13 -- beta 1: December 20, 2023 (compared to 1.12)
 
 * Alert slack "release-announcements" channel upon OSL release [#1740](https://github.com/AcademySoftwareFoundation/OpenShadingLangauge/pull/1740) [#1749](https://github.com/AcademySoftwareFoundation/OpenShadingLangauge/pull/1749)
 * Update pull request template [#1741](https://github.com/AcademySoftwareFoundation/OpenShadingLangauge/pull/1741)
+* Account for duplicate emails in the .mailmap [#1759](https://github.com/AcademySoftwareFoundation/OpenShadingLanguage/pull/1759)
 
 
 ---
diff --git a/CMakeLists.txt b/CMakeLists.txt
index b0e96253f..a0d7af7ce 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,7 +4,7 @@
 
 cmake_minimum_required (VERSION 3.15)
 
-set (OSL_VERSION "1.14.1.0")
+set (OSL_VERSION "1.14.1.1")
 set (OSL_VERSION_OVERRIDE "" CACHE STRING
      "Version override (use with caution)!")
 mark_as_advanced (OSL_VERSION_OVERRIDE)
@@ -39,6 +39,28 @@ if (CMAKE_VERSION VERSION_LESS 3.21)
     endif ()
 endif ()
 
+# Set up module path for our own cmake modules and add some esential ones
+list (APPEND CMAKE_MODULE_PATH
+      "${PROJECT_SOURCE_DIR}/src/cmake/modules"
+      "${PROJECT_SOURCE_DIR}/src/cmake")
+
+# Utilities
+include (colors)
+include (set_utils)
+include (check_is_enabled)
+include (fancy_add_executable)
+
+# If the user wants to use Conan to build dependencies, they will have done
+# this prior to the cmake config:
+#   cd <build area>
+#   conan install <source area>
+# and that will leave a conanbuildinfo.cmake in the build area for us.
+if (EXISTS ${CMAKE_BINARY_DIR}/conanbuildinfo.cmake)
+    include (${CMAKE_BINARY_DIR}/conanbuildinfo.cmake)
+    message (STATUS "Using Conan for dependencies")
+    conan_basic_setup()
+endif()
+
 if (NOT CMAKE_BUILD_TYPE)
     set (CMAKE_BUILD_TYPE "Release")
 endif ()
@@ -60,6 +82,7 @@ message (STATUS "Project build dir      = ${CMAKE_BINARY_DIR}")
 message (STATUS "Project install prefix = ${CMAKE_INSTALL_PREFIX}")
 message (STATUS "Configuration types    = ${CMAKE_CONFIGURATION_TYPES}")
 message (STATUS "Build type             = ${CMAKE_BUILD_TYPE}")
+message (STATUS "Supported release      = ${${PROJECT_NAME}_SUPPORTED_RELEASE}")
 
 # Make the build area layout look a bit more like the final dist layout
 set (CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
@@ -70,7 +93,6 @@ if ("${PROJECT_SOURCE_DIR}" STREQUAL "${CMAKE_BINARY_DIR}")
     message (FATAL_ERROR "Not allowed to run in-source build!")
 endif ()
 
-
 option (CMAKE_USE_FOLDERS "Use the FOLDER target property to organize targets into folders." ON)
 mark_as_advanced (CMAKE_USE_FOLDERS)
 if (CMAKE_USE_FOLDERS)
@@ -118,28 +140,28 @@ option (OSL_USTRINGREP_IS_HASH "Always use ustringhash for strings" OFF)
 
 set (OSL_NO_DEFAULT_TEXTURESYSTEM OFF CACHE BOOL "Do not use create a raw OIIO::TextureSystem")
 if (OSL_NO_DEFAULT_TEXTURESYSTEM)
-    add_definitions ("-DOSL_NO_DEFAULT_TEXTURESYSTEM=1")
+    add_compile_definitions (OSL_NO_DEFAULT_TEXTURESYSTEM=1)
 endif ()
 
 option (USE_FAST_MATH "Use fast math approximations (if no, then use system math library)" ON)
 if (USE_FAST_MATH)
-    add_definitions ("-DOSL_FAST_MATH=1")
+    add_compile_definitions (OSL_FAST_MATH=1)
 else ()
-    add_definitions ("-DOSL_FAST_MATH=0")
+    add_compile_definitions (OSL_FAST_MATH=0)
 endif ()
 
 option (OIIO_FMATH_SIMD_FRIENDLY "Make sure OIIO fmath functions are SIMD-friendly" OFF)
 if (OIIO_FMATH_SIMD_FRIENDLY)
-    add_definitions (-DOIIO_FMATH_SIMD_FRIENDLY=1)
+    add_compile_definitions (OIIO_FMATH_SIMD_FRIENDLY=1)
 endif ()
 
 # Define OSL_INTERNAL symbol only when building OSL itself, will not be
 # defined for downstream projects using OSL.
-add_definitions (-DOSL_INTERNAL=1)
+add_compile_definitions (OSL_INTERNAL=1)
 
 # To make sure we aren't relying on deprecated OIIO features, we define
 # OIIO_DISABLE_DEPRECATED before including any OIIO headers.
-add_definitions (-DOIIO_DISABLE_DEPRECATED=900000)
+add_compile_definitions (OIIO_DISABLE_DEPRECATED=900000)
 
 # Set the default namespace. For symbol hiding reasons, it's important that
 # the project name is a subset of the namespace name.
@@ -158,22 +180,24 @@ if (${PROJ_NAME}_NAMESPACE_INCLUDE_PATCH)
 endif ()
 message(STATUS "Setting Namespace to: ${PROJ_NAMESPACE_V}")
 
+# Define OSL_INTERNAL symbol only when building OSL itself, will not be
+# defined for downstream projects using OSL.
+add_definitions (-DOSL_INTERNAL=1)
 
-list (APPEND CMAKE_MODULE_PATH
-      "${PROJECT_SOURCE_DIR}/src/cmake/modules"
-      "${PROJECT_SOURCE_DIR}/src/cmake")
-
-# Helpful functions and macros for our project
-include (colors)
-include (check_is_enabled)
-include (checked_find_package)
+# To make sure we aren't relying on deprecated OIIO features, we define
+# OIIO_DISABLE_DEPRECATED before including any OIIO headers.
+add_definitions (-DOIIO_DISABLE_DEPRECATED=900000)
 
 # All the C++ and compiler related options and adjustments
 include (compiler)
 
+# Dependency finding utilities and all dependency-related options
+include (dependency_utils)
+
 # Utilities and options related to finding python and making python bindings
 include (pythonutils)
 
+# Dependency finding utilities and all dependency-related options
 include (externalpackages)
 include (flexbison)
 include (cuda_macros)
@@ -311,3 +335,5 @@ endif ()
 if (PROJECT_IS_TOP_LEVEL)
     include (packaging)
 endif ()
+
+print_package_notfound_report ()
diff --git a/INSTALL.md b/INSTALL.md
index 58ba76337..af474fdbb 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -21,11 +21,11 @@ NEW or CHANGED dependencies since the last major release are **bold**.
 
 * Build system: [CMake](https://cmake.org/) **3.15 or newer** (tested through 3.27)
 
-* A suitable C++14 or C++17 compiler to build OSL itself, which may be any of:
-   - GCC 6.1 or newer (tested through gcc 12.1)
-   - Clang 3.4 or newer (tested through clang 17)
+* A suitable C++17 compiler to build OSL itself, which may be any of:
+   - **GCC 9.3** or newer (tested through gcc 12.1)
+   - **Clang 5** or newer (tested through clang 18)
    - Microsoft Visual Studio 2017 or newer
-   - Intel C++ compiler icc version 17 or newer or LLVM-based icx compiler
+   - Intel C++ compiler **icc version 19** or newer or LLVM-based icx compiler
      version 2022 or newer.
 
 * **[OpenImageIO](http://openimageio.org) 2.4 or newer** (tested through 2.5 and master)
diff --git a/Makefile b/Makefile
index 4742da3f3..3c9b0dee2 100644
--- a/Makefile
+++ b/Makefile
@@ -349,7 +349,7 @@ help:
 	@echo "      VERBOSE=1                Show all compilation commands"
 	@echo "      STOP_ON_WARNING=0        Do not stop building if compiler warns"
 	@echo "      MYCC=xx MYCXX=yy         Use custom compilers"
-	@echo "      CMAKE_CXX_STANDARD=14    C++ standard to build with (default is 14)"
+	@echo "      CMAKE_CXX_STANDARD=17    C++ standard to build with (default is 17)"
 	@echo "      USE_LIBCPLUSPLUS=1       For clang, use libc++"
 	@echo "      GLIBCXX_USE_CXX11_ABI=1  For gcc, use the new string ABI"
 	@echo "      EXTRA_CPP_ARGS=          Additional args to the C++ command"
diff --git a/README.md b/README.md
index aa6953d95..710e802e6 100644
--- a/README.md
+++ b/README.md
@@ -426,7 +426,7 @@ nominated for major awards.)
   Obi-Wan Kenobi (series),
   The Boys (S3),
   Andor (S1)
-* **(2023 / upcoming)**
+* **(2023)**
   Ant-Man and the Wasp: Quantumania,
   The Mandalorian S3,
   The Magician's Elephant,
@@ -434,6 +434,12 @@ nominated for major awards.)
   Guardians of the Galaxy 3,
   Spider-Man: Across the Spider-Verse,
   Elemental,
+  The Marvels,
+  Leo
+* **(2024 / upcoming)**
+  Ghostbusters: Frozen Empire,
+  Inside Out 2,
+  In Your Dreams,
   ...
 
 
@@ -527,21 +533,21 @@ The current project leadership is documented in the
 Many people have contributed features, bug fixes, and other changes to OSL
 over the years: Steve Agland, Shane Ambler, Martijn Berger, Farchad
 Bidgolirad, Nicholas Bishop, Curtis Black, Rasmus Bonnedal, Solomon Boulos,
-Stefan Bruens, Stefan Büttner, Matthaus G. Chajdas, Clark Chen, Alejandro
-Conty, Damien Courtois, Dieter De Baets, Thomas Dinges, Daniel Dresser, Mads
-Drøschler, Peter Ellerington, Luke Emrose, Louis Feng, Mark Final, Henri
-Fousse, Stephen Friedman, Syoyo Fujita, Tim Grant, Larry Gritz, Nicolas
-Guiard, Euan Haahr, Derek Haase, Sven-Hendrik Haase, John Haddon, Niklas
-Harrysson, Daniel Heckenberg, Chris Hellmuth, Adrien Herubel, Dan Horák,
-Thiago Ize, Matt Johnson, Ronan Keryell, Chris Kulla, Elvic Liang, Max Liani,
-Adam Martinez, John Mertic, Bastien Montagne, Steena Monteiro, Patrick Mours,
-Alexis Oblet, Erich Ocean, Mikko Ohtamaa, Jino Park, Alexei Pawlow, Jay
-Reynolds, Declan Russell, Benoit Ruiz, Patrick Scheibe, Alex Schworer,
-Jonathan Scruggs, Sergey Sharybin, Mark Sisson, Sandip Shukla, Cliff Stein,
-Stephan Steinbach, Luya Tshimbalanga, Esteban Tovagliari, Brecht Van Lommel,
-Alexander von Knorring, Aidan Welch, Alex Wells, Roman Zulak. (Listed
-alphabetically; if we've left anybody out, it is inadvertent, please let us
-know.)
+Stefan Bruens, Stefan Büttner, Matthaus G. Chajdas, Clark Chen, Mehdi
+Chinoune, Alejandro Conty, Damien Courtois, Dieter De Baets, Thomas Dinges,
+Daniel Dresser, Mads Drøschler, Peter Ellerington, Luke Emrose, Louis Feng,
+Mark Final, Henri Fousse, Stephen Friedman, Syoyo Fujita, Tim Grant, Larry
+Gritz, Nicolas Guiard, Euan Haahr, Derek Haase, Sven-Hendrik Haase, John
+Haddon, Niklas Harrysson, Daniel Heckenberg, Chris Hellmuth, Adrien Herubel,
+Dan Horák, Thiago Ize, Matt Johnson, Ronan Keryell, Chris Kulla, Elvic Liang,
+Max Liani, Adam Martinez, John Mertic, Bastien Montagne, Steena Monteiro,
+Patrick Mours, Alexis Oblet, Erich Ocean, Mikko Ohtamaa, Jino Park, Alexei
+Pawlow, Mitch Prater, Jay Reynolds, Declan Russell, Benoit Ruiz, Patrick
+Scheibe, Alex Schworer, Jonathan Scruggs, Sergey Sharybin, Mark Sisson, Sandip
+Shukla, Cliff Stein, Stephan Steinbach, Luya Tshimbalanga, Esteban Tovagliari,
+Brecht Van Lommel, Thibault Vergne, Alexander von Knorring, Aidan Welch, Alex
+Wells, Roman Zulak. (Listed alphabetically; if we've left anybody out, it is
+inadvertent, please let us know.)
 
 We cannot possibly express sufficient gratitude to the managers at Sony
 Pictures Imageworks who allowed this project to proceed, supported it
diff --git a/doc/build_install/windows/build_osl.py b/doc/build_install/windows/build_osl.py
index d8eebb678..62a0e59d3 100644
--- a/doc/build_install/windows/build_osl.py
+++ b/doc/build_install/windows/build_osl.py
@@ -896,7 +896,7 @@ def InstallPtex_Windows(context, force, buildArgs):
         )
         PatchFile(
             "src\\tests\\CMakeLists.txt",
-            [("add_definitions(-DPTEX_STATIC)", "# add_definitions(-DPTEX_STATIC)")],
+            [("add_compile_definitions(PTEX_STATIC)", "# add_compile_definitions(PTEX_STATIC)")],
         )
 
         # Patch Ptex::String to export symbol for operator<<
@@ -1048,8 +1048,7 @@ def InstallOSL(context, force, buildArgs):
                 extraArgs.append("-DUSE_PYTHON=0")
 
         extraArgs.append("-DOSL_BUILD_TESTS=0")
-        # if you are using LLVM 10 or higher C++ should be set on 14
-        extraArgs.append("-DCMAKE_CXX_STANDARD=14")
+        extraArgs.append("-DCMAKE_CXX_STANDARD=17")
 
         # if you are using LLVM 10 or higher C++ should be set on 11
         # extraArgs.append("-DCMAKE_CXX_STANDARD=11")
@@ -1273,7 +1272,7 @@ def InstallOpenColorIO(context, force, buildArgs):
 option. This values for this option must take the form <library name>,<option>.
 For example:
 
-%(prog)s --build-args cxxflags=... OSL,-DCMAKE_CXX_STANDARD=14 ...
+%(prog)s --build-args cxxflags=... OSL,-DCMAKE_CXX_STANDARD=17 ...
 
 These arguments will be passed directly to the build system for the specified
 library. Multiple quotes may be needed to ensure arguments are passed on
diff --git a/src/build-scripts/build_opencolorio.bash b/src/build-scripts/build_opencolorio.bash
index a02acf099..9b54965c4 100755
--- a/src/build-scripts/build_opencolorio.bash
+++ b/src/build-scripts/build_opencolorio.bash
@@ -19,6 +19,7 @@ OPENCOLORIO_SOURCE_DIR=${OPENCOLORIO_SOURCE_DIR:=${LOCAL_DEPS_DIR}/OpenColorIO}
 OPENCOLORIO_BUILD_DIR=${OPENCOLORIO_BUILD_DIR:=${LOCAL_DEPS_DIR}/OpenColorIO-build}
 OPENCOLORIO_INSTALL_DIR=${OPENCOLORIO_INSTALL_DIR:=${LOCAL_DEPS_DIR}/dist}
 OPENCOLORIO_BUILD_TYPE=${OPENCOLORIO_BUILD_TYPE:=Release}
+OPENCOLORIO_CXX=${OPENCOLORIO_CXX:=g++}
 OPENCOLORIO_CXX_FLAGS=${OPENCOLORIO_CXX_FLAGS:="-Wno-unused-function -Wno-deprecated-declarations -Wno-cast-qual -Wno-write-strings"}
 # Just need libs:
 OPENCOLORIO_BUILDOPTS="-DOCIO_BUILD_APPS=OFF -DOCIO_BUILD_NUKE=OFF \
@@ -48,6 +49,7 @@ echo "Building OpenColorIO from commit" `git rev-parse --short HEAD`
 time cmake -S . -B ${OPENCOLORIO_BUILD_DIR} \
            -DCMAKE_BUILD_TYPE=${OPENCOLORIO_BUILD_TYPE} \
            -DCMAKE_INSTALL_PREFIX=${OPENCOLORIO_INSTALL_DIR} \
+           -DCMAKE_CXX_COMPILER=${OPENCOLORIO_CXX} \
            -DCMAKE_CXX_FLAGS="${OPENCOLORIO_CXX_FLAGS}" \
            ${OPENCOLORIO_BUILDOPTS}
 time cmake --build ${OPENCOLORIO_BUILD_DIR} --config Release --target install
diff --git a/src/build-scripts/ci-startup.bash b/src/build-scripts/ci-startup.bash
index a3d7b7d64..f90811b8f 100755
--- a/src/build-scripts/ci-startup.bash
+++ b/src/build-scripts/ci-startup.bash
@@ -21,6 +21,7 @@ mkdir -p $CCACHE_DIR
 export OSL_ROOT=$PWD/dist
 export DYLD_LIBRARY_PATH=$OSL_ROOT/lib:$DYLD_LIBRARY_PATH
 export LD_LIBRARY_PATH=$OSL_ROOT/lib:$LD_LIBRARY_PATH
+export OPENIMAGEIO_PLUGIN_PATH=$OSL_ROOT/lib:${OPENIMAGEIO_PLUGIN_PATH}
 export OIIO_LIBRARY_PATH=$OSL_ROOT/lib:${OIIO_LIBRARY_PATH}
 export LSAN_OPTIONS=suppressions=$PWD/src/build-scripts/nosanitize.txt
 export ASAN_OPTIONS=print_suppressions=0:detect_odr_violation=1
diff --git a/src/build-scripts/gh-installdeps.bash b/src/build-scripts/gh-installdeps.bash
index b40201e23..32e4035a3 100755
--- a/src/build-scripts/gh-installdeps.bash
+++ b/src/build-scripts/gh-installdeps.bash
@@ -12,12 +12,19 @@ set -ex
 # Install system packages when those are acceptable for dependencies.
 #
 if [[ "$ASWF_ORG" != ""  ]] ; then
-    # Using ASWF CentOS container
+    # Using ASWF container
 
     export PATH=/opt/rh/devtoolset-6/root/usr/bin:/usr/local/bin:$PATH
 
     #ls /etc/yum.repos.d
 
+    if [[ "$ASWF_VFXPLATFORM_VERSION" == "2021" || "$ASWF_VFXPLATFORM_VERSION" == "2022" ]] ; then
+        # CentOS 7 based containers need the now-nonexistant centos repo to be
+        # excluded or all the subsequent yum install commands will fail.
+        yum-config-manager --disable centos-sclo-rh && true
+        sed -i 's,^mirrorlist=,#,; s,^#baseurl=http://mirror\.centos\.org/centos/$releasever,baseurl=https://vault.centos.org/7.9.2009,' /etc/yum.repos.d/CentOS-Base.repo
+    fi
+
     sudo /usr/bin/yum install -y giflib giflib-devel && true
     # sudo /usr/bin/yum install -y ffmpeg ffmpeg-devel && true
 
diff --git a/src/cmake/checked_find_package.cmake b/src/cmake/checked_find_package.cmake
deleted file mode 100644
index d08306227..000000000
--- a/src/cmake/checked_find_package.cmake
+++ /dev/null
@@ -1,211 +0,0 @@
-# Copyright Contributors to the Open Shading Language project.
-# SPDX-License-Identifier: BSD-3-Clause
-# https://github.com/AcademySoftwareFoundation/OpenShadingLanguage
-
-
-set (REQUIRED_DEPS "" CACHE STRING
-     "Additional dependencies to consider required (semicolon-separated list, or ALL)")
-set (OPTIONAL_DEPS "" CACHE STRING
-     "Additional dependencies to consider optional (semicolon-separated list, or ALL)")
-option (ALWAYS_PREFER_CONFIG "Prefer a dependency's exported config file if it's available" OFF)
-
-
-# Utility function to list the names and values of all variables matching
-# the pattern (case-insensitive)
-function (dump_matching_variables pattern)
-    string (TOLOWER ${pattern} _pattern_lower)
-    get_cmake_property(_allvars VARIABLES)
-    list (SORT _allvars)
-    foreach (_var IN LISTS _allvars)
-        string (TOLOWER ${_var} _var_lower)
-        if (_var_lower MATCHES ${_pattern_lower})
-            message (STATUS "    ${_var} = ${${_var}}")
-        endif ()
-    endforeach ()
-endfunction ()
-
-
-
-# checked_find_package(Pkgname ...) is a wrapper for find_package, with the
-# following extra features:
-#   * If either `USE_Pkgname` or the all-uppercase `USE_PKGNAME` (or
-#     `ENABLE_Pkgname` or `ENABLE_PKGNAME`) exists as either a CMake or
-#     environment variable, is nonempty by contains a non-true/nonzero
-#     value, do not search for or use the package. The optional ENABLE <var>
-#     arguments allow you to override the name of the enabling variable. In
-#     other words, support for the dependency is presumed to be ON, unless
-#     turned off explicitly from one of these sources.
-#   * Print a message if the package is enabled but not found. This is based
-#     on ${Pkgname}_FOUND or $PKGNAME_FOUND.
-#   * Optional DEFINITIONS <string>... are passed to add_definitions if the
-#     package is found.
-#   * Optional SETVARIABLES <id>... is a list of CMake variables to set to
-#     TRUE if the package is found (they will not be set or changed if the
-#     package is not found).
-#   * Optional PRINT <list> is a list of variables that will be printed
-#     if the package is found, if VERBOSE is on.
-#   * Optional DEPS <list> is a list of hard dependencies; for each one, if
-#     dep_FOUND is not true, disable this package with an error message.
-#   * Optional ISDEPOF <downstream> names another package for which the
-#     present package is only needed because it's a dependency, and
-#     therefore if <downstream> is disabled, we don't bother with this
-#     package either.
-#   * Optional VERSION_MIN and VERSION_MAX, if supplied, give minimum and
-#     maximum versions that will be accepted. The min is inclusive, the max
-#     is exclusive (i.e., check for min <= version < max). Note that this is
-#     not the same as providing a version number to find_package, which
-#     checks compatibility, not minimum. Sometimes we really do just want to
-#     say a minimum or a range. (N.B. When our minimum CMake >= 3.19, the
-#     built-in way to do this is with version ranges passed to
-#     find_package.)
-#   * Optional RECOMMEND_MIN, if supplied, gives a minimum recommended
-#     version, accepting but warning if it is below this number (even
-#     if above the true minimum version accepted). The warning message
-#     can give an optional explanation, passed as RECOMMEND_MIN_REASON.
-#   * Optional PREFER_CONFIG, if supplied, tries to use an exported config
-#     file from the package before using a FindPackage.cmake module.
-#   * Optional DEBUG turns on extra debugging information related to how
-#     this package is found.
-#   * If either the optional PREFER_STATIC_LIBS argument to this macro, *or*
-#     CMake variable <Pkgname>_PREFER_STATIC_LIBS is true, then try to prefer
-#     static versions of any libraries found.
-#
-# N.B. This needs to be a macro, not a function, because the find modules
-# will set(blah val PARENT_SCOPE) and we need that to be the global scope,
-# not merely the scope for this function.
-macro (checked_find_package pkgname)
-    cmake_parse_arguments(_pkg   # prefix
-        # noValueKeywords:
-        "REQUIRED;PREFER_CONFIG;DEBUG;PREFER_STATIC_LIBS"
-        # singleValueKeywords:
-        "ENABLE;ISDEPOF;VERSION_MIN;VERSION_MAX;RECOMMEND_MIN;RECOMMEND_MIN_REASON"
-        # multiValueKeywords:
-        "DEFINITIONS;PRINT;DEPS;SETVARIABLES"
-        # argsToParse:
-        ${ARGN})
-    string (TOLOWER ${pkgname} pkgname_lower)
-    string (TOUPPER ${pkgname} pkgname_upper)
-    set (_pkg_VERBOSE ${VERBOSE})
-    if (_pkg_DEBUG)
-        set (_pkg_VERBOSE ON)
-    endif ()
-    if (NOT _pkg_VERBOSE)
-        set (${pkgname}_FIND_QUIETLY true)
-        set (${pkgname_upper}_FIND_QUIETLY true)
-    endif ()
-    if ("${pkgname}" IN_LIST REQUIRED_DEPS OR "ALL" IN_LIST REQUIRED_DEPS)
-        set (_pkg_REQUIRED 1)
-    endif ()
-    if ("${pkgname}" IN_LIST OPTIONAL_DEPS OR "ALL" IN_LIST OPTIONAL_DEPS)
-        set (_pkg_REQUIRED 0)
-    endif ()
-    set (_quietskip false)
-    check_is_enabled (${pkgname} _enable)
-    set (_disablereason "")
-    foreach (_dep ${_pkg_DEPS})
-        if (_enable AND NOT ${_dep}_FOUND)
-            set (_enable false)
-            set (ENABLE_${pkgname} OFF PARENT_SCOPE)
-            set (_disablereason "(because ${_dep} was not found)")
-        endif ()
-    endforeach ()
-    if (_pkg_ISDEPOF)
-        check_is_enabled (${_pkg_ISDEPOF} _dep_enabled)
-        if (NOT _dep_enabled)
-            set (_enable false)
-            set (_quietskip true)
-        endif ()
-    endif ()
-    set (_config_status "")
-    if (_enable OR _pkg_REQUIRED)
-        set (save_lib_path ${CMAKE_FIND_LIBRARY_SUFFIXES})
-        if (_pkg_PREFER_STATIC_LIBS OR ${pkgname}_PREFER_STATIC_LIBS)
-            set (CMAKE_FIND_LIBRARY_SUFFIXES .lib .a ${CMAKE_FIND_LIBRARY_SUFFIXES})
-        endif ()
-        if (${pkgname}_FOUND OR ${pkgname_upper}_FOUND)
-            # was already found
-        elseif (_pkg_PREFER_CONFIG OR ALWAYS_PREFER_CONFIG)
-            find_package (${pkgname} CONFIG ${_pkg_UNPARSED_ARGUMENTS})
-            if (${pkgname}_FOUND OR ${pkgname_upper}_FOUND)
-                set (_config_status "from CONFIG")
-            endif ()
-        endif ()
-        if (NOT (${pkgname}_FOUND OR ${pkgname_upper}_FOUND))
-            find_package (${pkgname} ${_pkg_UNPARSED_ARGUMENTS})
-        endif()
-        set (CMAKE_FIND_LIBRARY_SUFFIXES ${save_lib_path})
-        unset (save_lib_path)
-        if ((${pkgname}_FOUND OR ${pkgname_upper}_FOUND)
-              AND ${pkgname}_VERSION
-              AND (_pkg_VERSION_MIN OR _pkg_VERSION_MAX))
-            if ((_pkg_VERSION_MIN AND ${pkgname}_VERSION VERSION_LESS _pkg_VERSION_MIN)
-                  OR (_pkg_VERSION_MAX AND ${pkgname}_VERSION VERSION_GREATER _pkg_VERSION_MAX))
-                message (STATUS "${ColorRed}${pkgname} ${${pkgname}_VERSION} is outside the required range ${_pkg_VERSION_MIN}...${_pkg_VERSION_MAX} ${ColorReset}")
-                unset (${pkgname}_FOUND)
-                unset (${pkgname}_VERSION)
-                unset (${pkgname_upper}_FOUND)
-                unset (${pkgname_upper}_VERSION)
-            endif ()
-        endif ()
-        if (${pkgname}_FOUND OR ${pkgname_upper}_FOUND)
-            foreach (_vervar ${pkgname_upper}_VERSION ${pkgname}_VERSION_STRING
-                             ${pkgname_upper}_VERSION_STRING)
-                if (NOT ${pkgname}_VERSION AND ${_vervar})
-                    set (${pkgname}_VERSION ${${_vervar}})
-                endif ()
-            endforeach ()
-            message (STATUS "${ColorGreen}Found ${pkgname} ${${pkgname}_VERSION} ${_config_status}${ColorReset}")
-            add_definitions (${_pkg_DEFINITIONS})
-            foreach (_v IN LISTS _pkg_SETVARIABLES)
-                set (${_v} TRUE)
-            endforeach ()
-            if (_pkg_RECOMMEND_MIN)
-                if (${${pkgname}_VERSION} VERSION_LESS ${_pkg_RECOMMEND_MIN})
-                    message (STATUS "${ColorYellow}Recommend ${pkgname} >= ${_pkg_RECOMMEND_MIN} ${_pkg_RECOMMEND_MIN_REASON} ${ColorReset}")
-                endif ()
-            endif ()
-        else ()
-            message (STATUS "${ColorRed}${pkgname} library not found ${ColorReset}")
-            if (${pkgname}_ROOT)
-                message (STATUS "${ColorRed}    ${pkgname}_ROOT was: ${${pkgname}_ROOT} ${ColorReset}")
-            elseif ($ENV{${pkgname}_ROOT})
-                message (STATUS "${ColorRed}    ENV ${pkgname}_ROOT was: ${${pkgname}_ROOT} ${ColorReset}")
-            else ()
-                message (STATUS "${ColorRed}    Try setting ${pkgname}_ROOT ? ${ColorReset}")
-            endif ()
-            if (EXISTS "${PROJECT_SOURCE_DIR}/src/build-scripts/build_${pkgname}.bash")
-                message (STATUS "${ColorRed}    Maybe this will help:  src/build-scripts/build_${pkgname}.bash ${ColorReset}")
-            elseif (EXISTS "${PROJECT_SOURCE_DIR}/src/build-scripts/build_${pkgname_upper}.bash")
-                message (STATUS "${ColorRed}    Maybe this will help:  src/build-scripts/build_${pkgname_upper}.bash ${ColorReset}")
-            elseif (EXISTS "${PROJECT_SOURCE_DIR}/src/build-scripts/build_${pkgname_lower}.bash")
-                    message (STATUS "${ColorRed}    Maybe this will help:  src/build-scripts/build_${pkgname_lower}.bash ${ColorReset}")
-            elseif (EXISTS "${PROJECT_SOURCE_DIR}/src/build-scripts/build_lib${pkgname_lower}.bash")
-                    message (STATUS "${ColorRed}    Maybe this will help:  src/build-scripts/build_lib${pkgname_lower}.bash ${ColorReset}")
-            endif ()
-            if (_pkg_REQUIRED)
-                message (FATAL_ERROR "${ColorRed}${pkgname} is required, aborting.${ColorReset}")
-            endif ()
-        endif()
-        if (_pkg_VERBOSE AND (${pkgname}_FOUND OR ${pkgname_upper}_FOUND OR _pkg_DEBUG))
-            if (_pkg_DEBUG)
-                dump_matching_variables (${pkgname})
-            endif ()
-            set (_vars_to_print ${pkgname}_INCLUDES ${pkgname_upper}_INCLUDES
-                                ${pkgname}_INCLUDE_DIR ${pkgname_upper}_INCLUDE_DIR
-                                ${pkgname}_INCLUDE_DIRS ${pkgname_upper}_INCLUDE_DIRS
-                                ${pkgname}_LIBRARIES ${pkgname_upper}_LIBRARIES
-                                ${_pkg_PRINT})
-            list (REMOVE_DUPLICATES _vars_to_print)
-            foreach (_v IN LISTS _vars_to_print)
-                if (NOT "${${_v}}" STREQUAL "")
-                    message (STATUS "    ${_v} = ${${_v}}")
-                endif ()
-            endforeach ()
-        endif ()
-    else ()
-        if (NOT _quietskip)
-            message (STATUS "${ColorRed}Not using ${pkgname} -- disabled ${_disablereason} ${ColorReset}")
-        endif ()
-    endif ()
-endmacro()
-
diff --git a/src/cmake/colors.cmake b/src/cmake/colors.cmake
index 0b0621e59..2ea817f03 100644
--- a/src/cmake/colors.cmake
+++ b/src/cmake/colors.cmake
@@ -9,4 +9,9 @@ set (ColorReset       "${ColorEsc}[m")
 set (ColorRed         "${ColorEsc}[31m")
 set (ColorGreen       "${ColorEsc}[32m")
 set (ColorYellow      "${ColorEsc}[33m")
+set (ColorBlue        "${ColorEsc}[34m")
+set (ColorMagenta     "${ColorEsc}[35m")
+set (ColorBoldRed     "${ColorEsc}[1;31m")
+set (ColorBoldGreen   "${ColorEsc}[1;32m")
+set (ColorBoldYellow  "${ColorEsc}[1;33m")
 set (ColorBoldWhite   "${ColorEsc}[1;37m")
diff --git a/src/cmake/compiler.cmake b/src/cmake/compiler.cmake
index 4e86cc055..bb72aacc6 100644
--- a/src/cmake/compiler.cmake
+++ b/src/cmake/compiler.cmake
@@ -25,13 +25,22 @@ message (STATUS  "CMAKE_CXX_COMPILER_ID  = ${CMAKE_CXX_COMPILER_ID}")
 ###########################################################################
 # C++ language standard
 #
+set (CMAKE_CXX_MINIMUM 17)
 set (CMAKE_CXX_STANDARD 17 CACHE STRING
-     "C++ standard to build with (14, 17, 20, etc.)")
-set (DOWNSTREAM_CXX_STANDARD 14 CACHE STRING
+     "C++ standard to build with (17, 20, etc.) Minimum is ${CMAKE_CXX_MINIMUM}.")
+set (DOWNSTREAM_CXX_STANDARD 17 CACHE STRING
      "C++ minimum standard to impose on downstream clients")
 set (CMAKE_CXX_STANDARD_REQUIRED ON)
 set (CMAKE_CXX_EXTENSIONS OFF)
 message (STATUS "Building with C++${CMAKE_CXX_STANDARD}, downstream minimum C++${DOWNSTREAM_CXX_STANDARD}")
+if (CMAKE_CXX_STANDARD VERSION_LESS CMAKE_CXX_MINIMUM)
+    message (FATAL_ERROR "C++${CMAKE_CXX_STANDARD} is not supported, minimum is C++${CMAKE_CXX_MINIMUM}")
+endif ()
+# Remember the -std flags we need will be used later for custom Cuda builds
+set (CSTD_FLAGS "")
+if (CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_CLANG OR CMAKE_COMPILER_IS_INTEL)
+    set (CSTD_FLAGS "-std=c++${CMAKE_CXX_STANDARD}")
+endif ()
 
 
 ###########################################################################
@@ -183,8 +192,8 @@ if (CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_CLANG)
     # Options common to gcc and clang
 
     # Ensure this macro is set for stdint.h
-    add_definitions ("-D__STDC_LIMIT_MACROS")
-    add_definitions ("-D__STDC_CONSTANT_MACROS")
+    add_compile_definitions (__STDC_LIMIT_MACROS)
+    add_compile_definitions (__STDC_CONSTANT_MACROS)
     # this allows native instructions to be used for sqrtf instead of a function call
     add_compile_options ("-fno-math-errno")
 endif ()
@@ -197,11 +206,11 @@ endif ()
 if (MSVC)
     # Microsoft specific options
     string (REGEX REPLACE "/W[1-4]" "/W1" CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS})
-    add_definitions (-D_CRT_SECURE_NO_DEPRECATE)
-    add_definitions (-D_CRT_SECURE_NO_WARNINGS)
-    add_definitions (-D_CRT_NONSTDC_NO_WARNINGS)
-    add_definitions (-D_SCL_SECURE_NO_WARNINGS)
-    add_definitions (-DJAS_WIN_MSVC_BUILD)
+    add_compile_definitions (_CRT_SECURE_NO_DEPRECATE)
+    add_compile_definitions (_CRT_SECURE_NO_WARNINGS)
+    add_compile_definitions (_CRT_NONSTDC_NO_WARNINGS)
+    add_compile_definitions (_SCL_SECURE_NO_WARNINGS)
+    add_compile_definitions (JAS_WIN_MSVC_BUILD)
 endif (MSVC)
 
 if (${CMAKE_SYSTEM_NAME} STREQUAL "FreeBSD"
@@ -284,7 +293,7 @@ endif ()
 set (GLIBCXX_USE_CXX11_ABI "" CACHE STRING "For gcc, use the new C++11 library ABI (0|1)")
 if (CMAKE_COMPILER_IS_GNUCC AND ${GCC_VERSION} VERSION_GREATER_EQUAL 5.0)
     if (NOT ${GLIBCXX_USE_CXX11_ABI} STREQUAL "")
-        add_definitions ("-D_GLIBCXX_USE_CXX11_ABI=${GLIBCXX_USE_CXX11_ABI}")
+        add_compile_definitions (_GLIBCXX_USE_CXX11_ABI=${GLIBCXX_USE_CXX11_ABI})
     endif ()
 endif ()
 
@@ -368,7 +377,7 @@ option (CODECOV "Build code coverage tests" OFF)
 if (CODECOV AND (CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_CLANG))
     message (STATUS "Compiling for code coverage analysis")
     add_compile_options (-ftest-coverage -fprofile-arcs)
-    add_definitions ("-D${PROJ_NAME}_CODE_COVERAGE=1")
+    add_compile_definitions (${PROJ_NAME}_CODE_COVERAGE=1)
     link_libraries(gcov)
 endif ()
 
@@ -388,9 +397,9 @@ if (SANITIZE AND (CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_CLANG))
     add_compile_options (-g -fno-omit-frame-pointer)
     if (CMAKE_COMPILER_IS_GNUCC)
         # turn on glibcxx extra annotations to find vector writes past end
-        add_definitions ("-D_GLIBCXX_SANITIZE_VECTOR=1")
+        add_compile_definitions (_GLIBCXX_SANITIZE_VECTOR=1)
     endif ()
-    add_definitions ("-D${PROJECT_NAME}_SANITIZE=1")
+    add_compile_definitions (${PROJECT_NAME}_SANITIZE=1)
 endif ()
 
 
@@ -524,7 +533,7 @@ message(VERBOSE "Setting SOVERSION to: ${SOVERSION}")
 #
 option (BUILD_SHARED_LIBS "Build shared libraries (set to OFF to build static libs)" ON)
 if (NOT BUILD_SHARED_LIBS)
-    add_definitions (-D${PROJECT_NAME}_STATIC_DEFINE=1)
+    add_compile_definitions (${PROJECT_NAME}_STATIC_DEFINE=1)
 endif ()
 
 
@@ -549,7 +558,7 @@ endif ()
 # We expect our own CI runs to define env variable ${PROJECT_NAME}_CI
 #
 if (DEFINED ENV{${PROJECT_NAME}_CI})
-    add_definitions (-D${PROJ_NAME}_CI=1 -DBUILD_CI=1)
+    add_compile_definitions (${PROJ_NAME}_CI=1 BUILD_CI=1)
     if (APPLE)
         # Keep Mono framework from being incorrectly searched for include
         # files on GitHub Actions CI.
diff --git a/src/cmake/cuda_macros.cmake b/src/cmake/cuda_macros.cmake
index 046aefd20..e9857556d 100644
--- a/src/cmake/cuda_macros.cmake
+++ b/src/cmake/cuda_macros.cmake
@@ -11,7 +11,7 @@ set (CUDA_OPT_FLAG_CLANG "-O3" CACHE STRING "The optimization level to use when
 # host behavior, etc.
 set (CUDA_NO_FTZ OFF CACHE BOOL "Do not enable force-to-zero when compiling for CUDA")
 if (CUDA_NO_FTZ)
-    add_definitions ("-DOSL_CUDA_NO_FTZ=1")
+    add_compile_definitions (DOSL_CUDA_NO_FTZ=1)
 endif ()
 
 # Compile a CUDA file to PTX using NVCC
diff --git a/src/cmake/dependency_utils.cmake b/src/cmake/dependency_utils.cmake
new file mode 100644
index 000000000..e83e980e6
--- /dev/null
+++ b/src/cmake/dependency_utils.cmake
@@ -0,0 +1,620 @@
+# Copyright Contributors to the Open Shading Language project.
+# SPDX-License-Identifier: BSD-3-Clause
+# https://github.com/AcademySoftwareFoundation/OpenShadingLanguage
+
+
+set_cache (${PROJECT_NAME}_REQUIRED_DEPS ""
+           "Additional dependencies to consider required (semicolon-separated list, or ALL)")
+set_cache (${PROJECT_NAME}_OPTIONAL_DEPS ""
+           "Additional dependencies to consider optional (semicolon-separated list, or ALL)")
+set_option (${PROJECT_NAME}_ALWAYS_PREFER_CONFIG
+            "Prefer a dependency's exported config file if it's available" OFF)
+
+set_cache (${PROJECT_NAME}_BUILD_MISSING_DEPS ""
+     "Try to download and build any of these missing dependencies (or 'all')")
+set_cache (${PROJECT_NAME}_BUILD_LOCAL_DEPS ""
+     "Force local builds of these dependencies if possible (or 'all')")
+
+set_cache (${PROJECT_NAME}_LOCAL_DEPS_ROOT "${PROJECT_BINARY_DIR}/deps"
+           "Directory were we do local builds of dependencies")
+list (APPEND CMAKE_PREFIX_PATH ${${PROJECT_NAME}_LOCAL_DEPS_ROOT}/dist)
+include_directories(BEFORE ${${PROJECT_NAME}_LOCAL_DEPS_ROOT}/include)
+
+# Build type for locally built dependencies. Default to the same build type
+# as the current project.
+set_cache (${PROJECT_NAME}_DEPENDENCY_BUILD_TYPE ${CMAKE_BUILD_TYPE}
+           "Build type for locally built dependencies")
+set_option (${PROJECT_NAME}_DEPENDENCY_BUILD_VERBOSE
+            "Make dependency builds extra verbose" OFF)
+if (MSVC)
+    # I haven't been able to get Windows local dependency builds to work with
+    # static libraries, so default to shared libraries on Windows until we can
+    # figure it out.
+    set_cache (LOCAL_BUILD_SHARED_LIBS_DEFAULT ON
+               DOC "Should a local dependency build, if necessary, build shared libraries" ADVANCED)
+else ()
+    # On non-Windows, default to static libraries for local builds.
+    set_cache (LOCAL_BUILD_SHARED_LIBS_DEFAULT OFF
+               DOC "Should a local dependency build, if necessary, build shared libraries" ADVANCED)
+endif ()
+
+
+# Track all build deps we find with checked_find_package
+set (CFP_ALL_BUILD_DEPS_FOUND "")
+set (CFP_EXTERNAL_BUILD_DEPS_FOUND "")
+
+# Track all build deps we failed to find with checked_find_package
+set (CFP_ALL_BUILD_DEPS_NOTFOUND "")
+set (CFP_LOCALLY_BUILDABLE_DEPS_NOTFOUND "")
+
+# Track all build deps we found but were of inadequate version
+set (CFP_ALL_BUILD_DEPS_BADVERSION "")
+set (CFP_LOCALLY_BUILDABLE_DEPS_BADVERSION "")
+
+# Which dependencies did we build locally
+set (CFP_LOCALLY_BUILT_DEPS "")
+
+
+
+# Utility function to list the names and values of all variables matching
+# the pattern (case-insensitive)
+function (dump_matching_variables pattern)
+    string (TOLOWER ${pattern} _pattern_lower)
+    get_cmake_property(_allvars VARIABLES)
+    list (SORT _allvars)
+    foreach (_var IN LISTS _allvars)
+        string (TOLOWER ${_var} _var_lower)
+        if (_var_lower MATCHES ${_pattern_lower})
+            message (STATUS "    ${_var} = ${${_var}}")
+        endif ()
+    endforeach ()
+endfunction ()
+
+
+# Helper: Print a report about missing dependencies and give insructions on
+# how to turn on automatic local dependency building.
+function (print_package_notfound_report)
+    message (STATUS)
+    message (STATUS "${ColorBoldYellow}=========================================================================${ColorReset}")
+    message (STATUS "${ColorBoldYellow}= Dependency report                                                     =${ColorReset}")
+    message (STATUS "${ColorBoldYellow}=========================================================================${ColorReset}")
+    message (STATUS)
+    if (CFP_EXTERNAL_BUILD_DEPS_FOUND)
+        message (STATUS "${ColorBoldWhite}The following dependencies were found externally:${ColorReset}")
+        list (SORT CFP_EXTERNAL_BUILD_DEPS_FOUND CASE INSENSITIVE)
+        list (REMOVE_DUPLICATES CFP_EXTERNAL_BUILD_DEPS_FOUND)
+        foreach (_pkg IN LISTS CFP_EXTERNAL_BUILD_DEPS_FOUND)
+            message (STATUS "    ${_pkg} ${${_pkg}_VERSION}")
+        endforeach ()
+    endif ()
+    if (CFP_ALL_BUILD_DEPS_BADVERSION)
+        message (STATUS "${ColorBoldWhite}The following dependencies were found but were too old:${ColorReset}")
+        list (SORT CFP_ALL_BUILD_DEPS_BADVERSION CASE INSENSITIVE)
+        list (REMOVE_DUPLICATES CFP_ALL_BUILD_DEPS_BADVERSION)
+        foreach (_pkg IN LISTS CFP_ALL_BUILD_DEPS_BADVERSION)
+            if (_pkg IN_LIST CFP_LOCALLY_BUILT_DEPS)
+                message (STATUS "    ${_pkg} ${${_pkg}_NOT_FOUND_EXPLANATION} ${ColorMagenta}(${${_pkg}_VERSION} BUILT LOCALLY)${ColorReset}")
+            else ()
+                message (STATUS "    ${_pkg} ${${_pkg}_NOT_FOUND_EXPLANATION}")
+            endif ()
+        endforeach ()
+    endif ()
+    if (CFP_ALL_BUILD_DEPS_NOTFOUND)
+        message (STATUS "${ColorBoldWhite}The following dependencies were not found:${ColorReset}")
+        list (SORT CFP_ALL_BUILD_DEPS_NOTFOUND CASE INSENSITIVE)
+        list (REMOVE_DUPLICATES CFP_ALL_BUILD_DEPS_NOTFOUND)
+        foreach (_pkg IN LISTS CFP_ALL_BUILD_DEPS_NOTFOUND)
+            if (_pkg IN_LIST CFP_LOCALLY_BUILT_DEPS)
+                message (STATUS "    ${_pkg} ${_${_pkg}_version_range} ${${_pkg}_NOT_FOUND_EXPLANATION} ${ColorMagenta}(${${_pkg}_VERSION} BUILT LOCALLY)${ColorReset}")
+            else ()
+                message (STATUS "    ${_pkg} ${_${_pkg}_version_range} ${${_pkg}_NOT_FOUND_EXPLANATION}")
+            endif ()
+        endforeach ()
+    endif ()
+    if (CFP_LOCALLY_BUILDABLE_DEPS_NOTFOUND OR CFP_LOCALLY_BUILDABLE_DEPS_BADVERSION)
+        message (STATUS)
+        message (STATUS "${ColorBoldWhite}For some of these, we can build them locally:${ColorReset}")
+        foreach (_pkg IN LISTS CFP_LOCALLY_BUILDABLE_DEPS_NOTFOUND CFP_LOCALLY_BUILDABLE_DEPS_BADVERSION)
+            message (STATUS "    ${_pkg}")
+        endforeach ()
+        message (STATUS "${ColorBoldWhite}To build them automatically if not found, build again with option:${ColorReset}")
+        message (STATUS "    ${ColorBoldGreen}-D${PROJECT_NAME}_BUILD_MISSING_DEPS=all${ColorReset}")
+    endif ()
+    message (STATUS)
+    message (STATUS "${ColorBoldYellow}=========================================================================${ColorReset}")
+    message (STATUS)
+endfunction ()
+
+
+
+# Helper: called if a package is not found, print error messages, including
+# a fatal error if the package was required.
+function (handle_package_notfound pkgname required)
+    message (STATUS "${ColorRed}${pkgname} library not found ${ColorReset}")
+    if (${pkgname}_ROOT)
+        message (STATUS "    ${pkgname}_ROOT was: ${${pkgname}_ROOT}")
+    elseif ($ENV{${pkgname}_ROOT})
+        message (STATUS "    ENV ${pkgname}_ROOT was: ${${pkgname}_ROOT}")
+    else ()
+        message (STATUS "    Try setting ${pkgname}_ROOT ?")
+    endif ()
+    if (EXISTS "${PROJECT_SOURCE_DIR}/src/build-scripts/build_${pkgname}.bash")
+        message (STATUS "    Maybe this will help:  src/build-scripts/build_${pkgname}.bash")
+    elseif (EXISTS "${PROJECT_SOURCE_DIR}/src/build-scripts/build_${pkgname_upper}.bash")
+        message (STATUS "    Maybe this will help:  src/build-scripts/build_${pkgname_upper}.bash")
+    elseif (EXISTS "${PROJECT_SOURCE_DIR}/src/build-scripts/build_${pkgname_lower}.bash")
+            message (STATUS "    Maybe this will help:  src/build-scripts/build_${pkgname_lower}.bash")
+    elseif (EXISTS "${PROJECT_SOURCE_DIR}/src/build-scripts/build_lib${pkgname_lower}.bash")
+            message (STATUS "    Maybe this will help:  src/build-scripts/build_lib${pkgname_lower}.bash")
+    endif ()
+    if (required)
+        print_package_notfound_report()
+        message (FATAL_ERROR "${pkgname} is required, aborting.")
+    endif ()
+endfunction ()
+
+
+# Check whether the package's version (in pkgversion) lies within versionmin
+# and versionmax (inclusive). Store TRUE result variable if the version was in
+# range, FALSE if it was out of range. If it did not match, clear a bunch of
+# variables that may have been set by the find_package call (including
+# clearing the package's FOUND variable).
+function (reject_out_of_range_versions pkgname pkgversion versionmin versionmax result)
+    set (${result} FALSE PARENT_SCOPE)
+    string (TOUPPER ${pkgname} pkgname_upper)
+    # message (STATUS "roorv: ${pkgname} ${pkgversion} ${versionmin} ${versionmax}")
+    if (NOT ${pkgname}_FOUND AND NOT ${pkgname_upper}_FOUND)
+        message (STATUS "${pkgname} was not found")
+    elseif ("${pkgversion}" STREQUAL "")
+        message (ERROR "${pkgname} found but version was empty")
+    elseif (pkgversion VERSION_LESS versionmin
+            OR pkgversion VERSION_GREATER versionmax)
+        # message (STATUS "${ColorRed}${pkgname} ${pkgversion} is outside the required range ${versionmin}...${versionmax} ${ColorReset}")
+        # list (APPEND CFP_ALL_BUILD_DEPS_BADVERSION ${pkgname})
+        # if (${pkgname}_local_build_script_exists)
+        #     list (APPEND CFP_LOCALLY_BUILDABLE_DEPS_BADVERSION ${pkgname})
+        # endif ()
+        if (versionmax VERSION_GREATER_EQUAL 10000)
+            set (${pkgname}_NOT_FOUND_EXPLANATION
+                 "(found ${pkgversion}, needed >= ${versionmin})" PARENT_SCOPE)
+        else ()
+            set (${pkgname}_NOT_FOUND_EXPLANATION
+                 "(found ${pkgversion}, needed ${versionmin} ... ${versionmax})" PARENT_SCOPE)
+        endif ()
+        unset (${pkgname}_FOUND PARENT_SCOPE)
+        unset (${pkgname}_VERSION PARENT_SCOPE)
+        unset (${pkgname}_INCLUDE PARENT_SCOPE)
+        unset (${pkgname}_INCLUDES PARENT_SCOPE)
+        unset (${pkgname}_LIBRARY PARENT_SCOPE)
+        unset (${pkgname}_LIBRARIES PARENT_SCOPE)
+        unset (${pkgname_upper}_FOUND PARENT_SCOPE)
+        unset (${pkgname_upper}_VERSION PARENT_SCOPE)
+        unset (${pkgname_upper}_INCLUDE PARENT_SCOPE)
+        unset (${pkgname_upper}_INCLUDES PARENT_SCOPE)
+        unset (${pkgname_upper}_LIBRARY PARENT_SCOPE)
+        unset (${pkgname_upper}_LIBRARIES PARENT_SCOPE)
+    else ()
+        # Version matched the range
+        set (${result} TRUE PARENT_SCOPE)
+        # message (STATUS "${pkgname} ${pkgversion} is INSIDE the required range ${versionmin}...${versionmax}")
+    endif ()
+endfunction ()
+
+
+
+# checked_find_package(Pkgname ...) is a wrapper for find_package, with the
+# following extra features:
+#   * If either `USE_Pkgname` or the all-uppercase `USE_PKGNAME` (or
+#     `ENABLE_Pkgname` or `ENABLE_PKGNAME`) exists as either a CMake or
+#     environment variable, is nonempty by contains a non-true/nonzero
+#     value, do not search for or use the package. The optional ENABLE <var>
+#     arguments allow you to override the name of the enabling variable. In
+#     other words, support for the dependency is presumed to be ON, unless
+#     turned off explicitly from one of these sources.
+#   * Print a message if the package is enabled but not found. This is based
+#     on ${Pkgname}_FOUND or $PKGNAME_FOUND.
+#   * Optional DEFINITIONS <string>... are passed to add_compile_definitions
+#     if the package is found.
+#   * Optional SETVARIABLES <id>... is a list of CMake variables to set to
+#     TRUE if the package is found (they will not be set or changed if the
+#     package is not found).
+#   * Optional PRINT <list> is a list of variables that will be printed
+#     if the package is found, if VERBOSE is on.
+#   * Optional DEPS <list> is a list of hard dependencies; for each one, if
+#     dep_FOUND is not true, disable this package with an error message.
+#   * Optional ISDEPOF <downstream> names another package for which the
+#     present package is only needed because it's a dependency, and
+#     therefore if <downstream> is disabled, we don't bother with this
+#     package either.
+#   * Optional VERSION_MIN and VERSION_MAX, if supplied, give minimum and
+#     maximum versions that will be accepted. The min is inclusive, the max
+#     is exclusive (i.e., check for min <= version < max). Note that this is
+#     not the same as providing a version number to find_package, which
+#     checks compatibility, not minimum. Sometimes we really do just want to
+#     say a minimum or a range. (N.B. When our minimum CMake >= 3.19, the
+#     built-in way to do this is with version ranges passed to
+#     find_package.)
+#   * Optional RECOMMEND_MIN, if supplied, gives a minimum recommended
+#     version, accepting but warning if it is below this number (even
+#     if above the true minimum version accepted). The warning message
+#     can give an optional explanation, passed as RECOMMEND_MIN_REASON.
+#   * Optional CONFIG, if supplied, only accepts the package from an
+#     exported config and never uses a FindPackage.cmake module.
+#   * Optional PREFER_CONFIG, if supplied, tries to use an exported config
+#     file from the package before using a FindPackage.cmake module.
+#   * Optional DEBUG turns on extra debugging information related to how
+#     this package is found.
+#   * Found package "name version" or "name NONE" are accumulated in the list
+#     CFP_ALL_BUILD_DEPS_FOUND. If the optional NO_RECORD_NOTFOUND is
+#     supplied, un-found packags will not be recorded.
+#   * Optional BUILD_LOCAL, if supplied, if followed by a token that specifies
+#     the conditions under which to build the package locally by including a
+#     script included in src/cmake/build_${pkgname}.cmake. If the condition is
+#     "always", it will attempt to do so unconditionally. If "missing", it
+#     will only do so if the package is not found. Also note that if the
+#     global ${PROJECT_NAME}_BUILD_LOCAL_DEPS contains the package name or
+#     is "all", it will behave as if set to "always", and if the variable
+#     ${PROJECT_NAME}_BUILD_MISSING_DEPS contains the package name or is
+#     "all", it will behave as if set to "missing".
+#   * Optional NO_FP_RANGE_CHECK avoids passing the version range to
+#     find_package itself.
+#
+# Explanation about local builds:
+#
+# If the package isn't found externally in the usual places or doesn't meet
+# the version criteria, we check for the existance of a file at
+# `src/build-scripts/build_<pkgname>.cmake`. If that exists, we include and
+# execute it. The script can do whatever it wants, but should either (a)
+# somehow set up the link targets that would have been found had the package
+# had been found, or (b) set the variable `<pkgname>_REFIND` to a true value
+# and have done something to ensure that the package will be found if we try a
+# second time. For (b), typically that might mean downloading the package and
+# building it locally, and then setting the `<pkgname>_ROOT` to where it's
+# installed.
+#
+# N.B. This needs to be a macro, not a function, because the find modules
+# will set(blah val PARENT_SCOPE) and we need that to be the global scope,
+# not merely the scope for this function.
+macro (checked_find_package pkgname)
+    #
+    # Various setup logic
+    #
+    cmake_parse_arguments(_pkg   # prefix
+        # noValueKeywords:
+        "REQUIRED;CONFIG;PREFER_CONFIG;DEBUG;NO_RECORD_NOTFOUND;NO_FP_RANGE_CHECK"
+        # singleValueKeywords:
+        "ENABLE;ISDEPOF;VERSION_MIN;VERSION_MAX;RECOMMEND_MIN;RECOMMEND_MIN_REASON;BUILD_LOCAL"
+        # multiValueKeywords:
+        "DEFINITIONS;PRINT;DEPS;SETVARIABLES"
+        # argsToParse:
+        ${ARGN})
+    string (TOLOWER ${pkgname} pkgname_lower)
+    string (TOUPPER ${pkgname} pkgname_upper)
+    set (_pkg_VERBOSE ${VERBOSE})
+    if (_pkg_DEBUG)
+        set (_pkg_VERBOSE ON)
+    endif ()
+    if (NOT _pkg_VERBOSE)
+        set (${pkgname}_FIND_QUIETLY true)
+        set (${pkgname_upper}_FIND_QUIETLY true)
+    endif ()
+    if ("${pkgname}" IN_LIST ${PROJECT_NAME}_REQUIRED_DEPS OR "ALL" IN_LIST ${PROJECT_NAME}_REQUIRED_DEPS)
+        set (_pkg_REQUIRED 1)
+    endif ()
+    if ("${pkgname}" IN_LIST ${PROJECT_NAME}_OPTIONAL_DEPS OR "ALL" IN_LIST ${PROJECT_NAME}_OPTIONAL_DEPS)
+        set (_pkg_REQUIRED 0)
+    endif ()
+    # string (TOLOWER "${_pkg_BUILD_LOCAL}" _pkg_BUILD_LOCAL)
+    if ("${pkgname}" IN_LIST ${PROJECT_NAME}_BUILD_LOCAL_DEPS
+        OR ${PROJECT_NAME}_BUILD_LOCAL_DEPS STREQUAL "all")
+        set (_pkg_BUILD_LOCAL "always")
+    elseif ("${pkgname}" IN_LIST ${PROJECT_NAME}_BUILD_MISSING_DEPS
+            OR ${PROJECT_NAME}_BUILD_MISSING_DEPS STREQUAL "all")
+        set_if_not (_pkg_BUILD_LOCAL "missing")
+    endif ()
+    set (${pkgname}_local_build_script "${PROJECT_SOURCE_DIR}/src/cmake/build_${pkgname}.cmake")
+    if (EXISTS ${${pkgname}_local_build_script})
+        set (${pkgname}_local_build_script_exists TRUE)
+    endif ()
+    if (_pkg_BUILD_LOCAL AND NOT EXISTS "${${pkgname}_local_build_script}")
+        unset (_pkg_BUILD_LOCAL)
+    endif ()
+    set (_quietskip false)
+    check_is_enabled (${pkgname} _enable)
+    set (_disablereason "")
+    foreach (_dep ${_pkg_DEPS})
+        if (_enable AND NOT ${_dep}_FOUND)
+            set (_enable false)
+            set (ENABLE_${pkgname} OFF PARENT_SCOPE)
+            set (_disablereason "(because ${_dep} was not found)")
+        endif ()
+    endforeach ()
+    if (_pkg_ISDEPOF)
+        check_is_enabled (${_pkg_ISDEPOF} _dep_enabled)
+        if (NOT _dep_enabled)
+            set (_enable false)
+            set (_quietskip true)
+        endif ()
+    endif ()
+    set (_config_status "")
+    unset (_${pkgname}_version_range)
+    if (_pkg_BUILD_LOCAL AND NOT _pkg_NO_FP_RANGE_CHECK)
+        # SKIP THIS -- I find it unreliable because the package's exported
+        # PKGConfigVersion.cmake has might have arbitrary rules. Use our own
+        # MIN_VERSION and MAX_VERSION parameters to manually check instead.
+        #
+        if (_pkg_VERSION_MIN AND _pkg_VERSION_MAX AND CMAKE_VERSION VERSION_GREATER_EQUAL 3.19)
+            set (_${pkgname}_version_range "${_pkg_VERSION_MIN}...<${_pkg_VERSION_MAX}")
+        elseif (_pkg_VERSION_MIN)
+            set (_${pkgname}_version_range "${_pkg_VERSION_MIN}")
+        endif ()
+    endif ()
+    set_if_not (_pkg_VERSION_MIN "0.0.1")
+    set_if_not (_pkg_VERSION_MAX "10000.0.0")
+    #
+    # Now we try to find or build
+    #
+    set (${pkgname}_FOUND FALSE)
+    set (${pkgname}_LOCAL_BUILD FALSE)
+    if (_enable OR _pkg_REQUIRED)
+        # Unless instructed not to, try to find the package externally
+        # installed.
+        if (${pkgname}_FOUND OR ${pkgname_upper}_FOUND OR _pkg_BUILD_LOCAL STREQUAL "always")
+            # was already found, or we're forcing a local build
+        elseif (_pkg_CONFIG OR _pkg_PREFER_CONFIG OR ${PROJECT_NAME}_ALWAYS_PREFER_CONFIG)
+            find_package (${pkgname} ${_${pkgname}_version_range} CONFIG ${_pkg_UNPARSED_ARGUMENTS})
+            reject_out_of_range_versions (${pkgname} "${${pkgname}_VERSION}"
+                                          ${_pkg_VERSION_MIN} ${_pkg_VERSION_MAX}
+                                          _pkg_version_in_range)
+            if (${pkgname}_FOUND OR ${pkgname_upper}_FOUND)
+                set (_config_status "from CONFIG")
+            endif ()
+        endif ()
+        if (NOT ${pkgname}_FOUND AND NOT ${pkgname_upper}_FOUND AND NOT _pkg_BUILD_LOCAL STREQUAL "always" AND NOT _pkg_CONFIG)
+            find_package (${pkgname} ${_${pkgname}_version_range} ${_pkg_UNPARSED_ARGUMENTS})
+        endif()
+        if (NOT ${pkgname}_FOUND AND NOT ${pkgname_upper}_FOUND)
+            list (APPEND CFP_ALL_BUILD_DEPS_NOTFOUND ${pkgname})
+            if (${pkgname}_local_build_script_exists)
+                list (APPEND CFP_LOCALLY_BUILDABLE_DEPS_NOTFOUND ${pkgname})
+            endif ()
+        endif ()
+        # Some FindPackage modules set nonstandard variables for the versions
+        if (NOT ${pkgname}_VERSION AND ${pkgname_upper}_VERSION)
+            set (${pkgname}_VERSION ${${pkgname_upper}_VERSION})
+        endif ()
+        if (NOT ${pkgname}_VERSION AND ${pkgname_upper}_VERSION_STRING)
+            set (${pkgname}_VERSION ${${pkgname_upper}_VERSION_STRING})
+        endif ()
+        # If the package was found but the version is outside the required
+        # range, unset the relevant variables so that we can try again fresh.
+        if ((${pkgname}_FOUND OR ${pkgname_upper}_FOUND) AND ${pkgname}_VERSION)
+            reject_out_of_range_versions (${pkgname} ${${pkgname}_VERSION}
+                                          ${_pkg_VERSION_MIN} ${_pkg_VERSION_MAX}
+                                          _pkg_version_in_range)
+            if (_pkg_version_in_range)
+                list (APPEND CFP_EXTERNAL_BUILD_DEPS_FOUND ${pkgname})
+            else ()
+                message (STATUS "${ColorRed}${pkgname} ${${pkgname}_VERSION} is outside the required range ${_pkg_VERSION_MIN}...${_pkg_VERSION_MAX} ${ColorReset}")
+                list (APPEND CFP_ALL_BUILD_DEPS_BADVERSION ${pkgname})
+                if (${pkgname}_local_build_script_exists)
+                    list (APPEND CFP_LOCALLY_BUILDABLE_DEPS_BADVERSION ${pkgname})
+                endif ()
+            endif ()
+        endif ()
+        # If we haven't found the package yet and are allowed to build a local
+        # version, and a build_<pkgname>.cmake exists, include it to build the
+        # package locally.
+        if (NOT ${pkgname}_FOUND AND NOT ${pkgname_upper}_FOUND
+            AND (_pkg_BUILD_LOCAL STREQUAL "always" OR _pkg_BUILD_LOCAL STREQUAL "missing")
+            AND EXISTS "${${pkgname}_local_build_script}")
+            message (STATUS "${ColorMagenta}Building package ${pkgname} ${${pkgname}_VERSION} locally${ColorReset}")
+            list(APPEND CMAKE_MESSAGE_INDENT "        ")
+            include("${${pkgname}_local_build_script}")
+            list(POP_BACK CMAKE_MESSAGE_INDENT)
+            # set (${pkgname}_FOUND TRUE)
+            set (${pkgname}_LOCAL_BUILD TRUE)
+            list (APPEND CFP_LOCALLY_BUILT_DEPS ${pkgname})
+            list (REMOVE_ITEM CFP_LOCALLY_BUILDABLE_DEPS_NOTFOUND ${pkgname})
+        endif()
+        # If the local build instrctions set <pkgname>_REFIND, then try a find
+        # again to pick up the local one, at which point we can proceed as if
+        # it had been found externally all along. The local build script can
+        # also optionally set the following hints:
+        #   ${pkgname}_REFIND_VERSION : the version that was just installed,
+        #                               to specifically find.
+        #   ${pkgname}_REFIND_ARGS    : additional arguments to pass to find_package
+        if (${pkgname}_REFIND)
+            message (STATUS "Refinding ${pkgname} with ${pkgname}_ROOT=${${pkgname}_ROOT}")
+            find_package (${pkgname} ${_pkg_UNPARSED_ARGUMENTS} ${${pkgname}_REFIND_ARGS})
+            unset (${pkgname}_REFIND)
+        endif()
+        # It's all downhill from here: if we found the package, follow the
+        # various instructions we got about variables to set, compile
+        # definitions to add, etc.
+        if (${pkgname}_FOUND OR ${pkgname_upper}_FOUND)
+            foreach (_vervar ${pkgname_upper}_VERSION ${pkgname}_VERSION_STRING
+                             ${pkgname_upper}_VERSION_STRING)
+                if (NOT ${pkgname}_VERSION AND ${_vervar})
+                    set (${pkgname}_VERSION ${${_vervar}})
+                endif ()
+            endforeach ()
+            message (STATUS "${ColorGreen}Found ${pkgname} ${${pkgname}_VERSION} ${_config_status}${ColorReset}")
+            add_compile_definitions (${_pkg_DEFINITIONS})
+            foreach (_v IN LISTS _pkg_SETVARIABLES)
+                set (${_v} TRUE)
+            endforeach ()
+            if (_pkg_RECOMMEND_MIN)
+                if (${${pkgname}_VERSION} VERSION_LESS ${_pkg_RECOMMEND_MIN})
+                    message (STATUS "${ColorYellow}Recommend ${pkgname} >= ${_pkg_RECOMMEND_MIN} ${_pkg_RECOMMEND_MIN_REASON} ${ColorReset}")
+                endif ()
+            endif ()
+            string (STRIP "${pkgname} ${${pkgname}_VERSION}" app_)
+            list (APPEND CFP_ALL_BUILD_DEPS_FOUND "${app_}")
+        else ()
+            handle_package_notfound (${pkgname} ${_pkg_REQUIRED})
+            if (NOT _pkg_NO_RECORD_NOTFOUND)
+                list (APPEND CFP_ALL_BUILD_DEPS_FOUND "${pkgname} NONE")
+            endif ()
+        endif()
+        if (_pkg_VERBOSE AND (${pkgname}_FOUND OR ${pkgname_upper}_FOUND OR _pkg_DEBUG))
+            if (_pkg_DEBUG)
+                dump_matching_variables (${pkgname})
+            endif ()
+            set (_vars_to_print ${pkgname}_INCLUDES ${pkgname_upper}_INCLUDES
+                                ${pkgname}_INCLUDE_DIR ${pkgname_upper}_INCLUDE_DIR
+                                ${pkgname}_INCLUDE_DIRS ${pkgname_upper}_INCLUDE_DIRS
+                                ${pkgname}_LIBRARIES ${pkgname_upper}_LIBRARIES
+                                ${_pkg_PRINT})
+            list (REMOVE_DUPLICATES _vars_to_print)
+            foreach (_v IN LISTS _vars_to_print)
+                if (NOT "${${_v}}" STREQUAL "")
+                    message (STATUS "    ${_v} = ${${_v}}")
+                endif ()
+            endforeach ()
+        endif ()
+    else ()
+        if (NOT _quietskip)
+            message (STATUS "${ColorRed}Not using ${pkgname} -- disabled ${_disablereason} ${ColorReset}")
+        endif ()
+    endif ()
+    # unset (_${pkgname}_version_range)
+endmacro()
+
+
+
+# Helper to build a dependency with CMake. Given a package name, git repo and
+# tag, and optional cmake args, it will clone the repo into the surrounding
+# project's build area, configures, and build sit, and installs it into a
+# special dist area (unless the NOINSTALL option is given).
+#
+# After running, it leaves the following variables set:
+#   ${pkgname}_LOCAL_SOURCE_DIR
+#   ${pkgname}_LOCAL_BUILD_DIR
+#   ${pkgname}_LOCAL_INSTALL_DIR
+#
+# Unless NOINSTALL is specified, the after the installation step, the
+# installation directory will be added to the CMAKE_PREFIX_PATH and also will
+# be stored in the ${pkgname}_ROOT variable.
+#
+macro (build_dependency_with_cmake pkgname)
+    cmake_parse_arguments(_pkg   # prefix
+        # noValueKeywords:
+        "NOINSTALL"
+        # singleValueKeywords:
+        "GIT_REPOSITORY;GIT_TAG;VERSION"
+        # multiValueKeywords:
+        "CMAKE_ARGS"
+        # argsToParse:
+        ${ARGN})
+
+    message (STATUS "Building local ${pkgname} ${_pkg_VERSION} from ${_pkg_GIT_REPOSITORY}")
+
+    set (${pkgname}_LOCAL_SOURCE_DIR "${${PROJECT_NAME}_LOCAL_DEPS_ROOT}/${pkgname}")
+    set (${pkgname}_LOCAL_BUILD_DIR "${${PROJECT_NAME}_LOCAL_DEPS_ROOT}/${pkgname}-build")
+    set (${pkgname}_LOCAL_INSTALL_DIR "${${PROJECT_NAME}_LOCAL_DEPS_ROOT}/dist")
+    message (STATUS "Downloading local ${_pkg_GIT_REPOSITORY}")
+
+    set (_pkg_quiet OUTPUT_QUIET)
+
+    # Clone the repo if we don't already have it
+    find_package (Git REQUIRED)
+    if (NOT IS_DIRECTORY ${${pkgname}_LOCAL_SOURCE_DIR})
+        execute_process(COMMAND ${GIT_EXECUTABLE} clone ${_pkg_GIT_REPOSITORY}
+                                -b ${_pkg_GIT_TAG} --depth 1 -q
+                                ${${pkgname}_LOCAL_SOURCE_DIR}
+                        ${_pkg_quiet})
+        if (NOT IS_DIRECTORY ${${pkgname}_LOCAL_SOURCE_DIR})
+            message (FATAL_ERROR "Could not download ${_pkg_GIT_REPOSITORY}")
+        endif ()
+    endif ()
+    execute_process(COMMAND ${GIT_EXECUTABLE} checkout ${_pkg_GIT_TAG}
+                    WORKING_DIRECTORY ${${pkgname}_LOCAL_SOURCE_DIR}
+                    ${_pkg_quiet})
+
+    # Configure the package
+    if (${PROJECT_NAME}_DEPENDENCY_BUILD_VERBOSE)
+        set (_pkg_cmake_verbose -DCMAKE_VERBOSE_MAKEFILE=ON
+                                -DCMAKE_MESSAGE_LOG_LEVEL=VERBOSE
+                                -DCMAKE_RULE_MESSAGES=ON
+                                )
+    else ()
+        set (_pkg_cmake_verbose -DCMAKE_VERBOSE_MAKEFILE=OFF
+                                -DCMAKE_MESSAGE_LOG_LEVEL=ERROR
+                                -DCMAKE_RULE_MESSAGES=OFF
+                                -Wno-dev
+                                )
+    endif ()
+
+    execute_process (COMMAND
+        ${CMAKE_COMMAND}
+            # Put things in our special local build areas
+                -S ${${pkgname}_LOCAL_SOURCE_DIR}
+                -B ${${pkgname}_LOCAL_BUILD_DIR}
+                -DCMAKE_INSTALL_PREFIX=${${pkgname}_LOCAL_INSTALL_DIR}
+            # Same build type as us
+                -DCMAKE_BUILD_TYPE=${${PROJECT_NAME}_DEPENDENCY_BUILD_TYPE}
+            # Shhhh
+                -DCMAKE_MESSAGE_INDENT="        "
+                -DCMAKE_COMPILE_WARNING_AS_ERROR=OFF
+                ${_pkg_cmake_verbose}
+            # Build args passed by caller
+                ${_pkg_CMAKE_ARGS}
+        ${pkg_quiet}
+        )
+
+    # Build the package
+    execute_process (COMMAND ${CMAKE_COMMAND}
+                        --build ${${pkgname}_LOCAL_BUILD_DIR}
+                        --config ${${PROJECT_NAME}_DEPENDENCY_BUILD_TYPE}
+                     ${pkg_quiet}
+                    )
+
+    # Install the project, unless instructed not to do so
+    if (NOT _pkg_NOINSTALL)
+        execute_process (COMMAND ${CMAKE_COMMAND}
+                            --build ${${pkgname}_LOCAL_BUILD_DIR}
+                            --config ${${PROJECT_NAME}_DEPENDENCY_BUILD_TYPE}
+                            --target install
+                         ${pkg_quiet}
+                        )
+        set (${pkgname}_ROOT ${${pkgname}_LOCAL_INSTALL_DIR})
+        list (APPEND CMAKE_PREFIX_PATH ${${pkgname}_LOCAL_INSTALL_DIR})
+    endif ()
+endmacro ()
+
+
+# Copy libraries from a locally-built dependency into our own install area.
+# This is useful for dynamic libraries that we need to be part of our own
+# installation.
+macro (install_local_dependency_libs pkgname libname)
+    # We need to include the Imath dynamic libraries in our own install.
+    # get_target_property(_lib_files Imath::Imath INTERFACE_LINK_LIBRARIES)
+    set (patterns ${ARGN})
+    file (GLOB _lib_files
+            "${${pkgname}_LOCAL_INSTALL_DIR}/lib/*${libname}*"
+            "${${pkgname}_LOCAL_INSTALL_DIR}/lib/${${PROJECT_NAME}_DEPENDENCY_BUILD_TYPE}/*${libname}*"
+         )
+    install (FILES ${_lib_files} TYPE LIB)
+    # message("${pkgname}_LOCAL_INSTALL_DIR = ${${pkgname}_LOCAL_INSTALL_DIR}")
+    # message("  lib files = ${_lib_files}")
+    if (WIN32)
+        # On Windows, check for DLLs, which go in the bin directory
+        file (GLOB _lib_files
+                "${${pkgname}_LOCAL_INSTALL_DIR}/bin/*${libname}*.dll"
+                "${${pkgname}_LOCAL_INSTALL_DIR}/bin/${${PROJECT_NAME}_DEPENDENCY_BUILD_TYPE}/*${libname}*.dll"
+             )
+        # message("  dll files = ${_lib_files}")
+        install (FILES ${_lib_files} TYPE BIN)
+    endif ()
+    unset (_lib_files)
+endmacro ()
+
+
+# If the target `newalias` doesn't yet exist but `realtarget` does, create an
+# alias for `newalias` to mean the real target.
+macro (alias_library_if_not_exists newalias realtarget)
+    if (NOT TARGET ${newalias} AND TARGET ${realtarget})
+        add_library(${newalias} ALIAS ${realtarget})
+    endif ()
+endmacro ()
diff --git a/src/cmake/externalpackages.cmake b/src/cmake/externalpackages.cmake
index 2d33e6542..b92543b62 100644
--- a/src/cmake/externalpackages.cmake
+++ b/src/cmake/externalpackages.cmake
@@ -50,7 +50,7 @@ checked_find_package (OpenEXR REQUIRED
 # install version of 2.x.
 include_directories(BEFORE ${IMATH_INCLUDES})
 if (MSVC AND NOT LINKSTATIC)
-    add_definitions (-DOPENEXR_DLL) # Is this needed for new versions?
+    add_compile_definitions (OPENEXR_DLL) # Is this needed for new versions?
 endif ()
 
 if (OPENEXR_VERSION VERSION_GREATER_EQUAL 2.5.99)
@@ -63,7 +63,7 @@ endif ()
 # OpenImageIO
 checked_find_package (OpenImageIO REQUIRED
                       VERSION_MIN 2.4
-                      DEFINITIONS -DOIIO_HIDE_FORMAT=1)
+                      DEFINITIONS OIIO_HIDE_FORMAT=1)
 
 checked_find_package (pugixml REQUIRED
                       VERSION_MIN 1.8)
@@ -80,10 +80,10 @@ link_directories ("${LLVM_LIB_DIR}")
 # Extract and concatenate major & minor, remove wayward patches,
 # dots, and "svn" or other suffixes.
 string (REGEX REPLACE "([0-9]+)\\.([0-9]+).*" "\\1\\2" OSL_LLVM_VERSION ${LLVM_VERSION})
-add_definitions (-DOSL_LLVM_VERSION=${OSL_LLVM_VERSION})
-add_definitions (-DOSL_LLVM_FULL_VERSION="${LLVM_VERSION}")
+add_compile_definitions (OSL_LLVM_VERSION=${OSL_LLVM_VERSION})
+add_compile_definitions (OSL_LLVM_FULL_VERSION="${LLVM_VERSION}")
 if (LLVM_NAMESPACE)
-    add_definitions ("-DLLVM_NAMESPACE=${LLVM_NAMESPACE}")
+    add_compile_definitions (LLVM_NAMESPACE=${LLVM_NAMESPACE})
 endif ()
 if (APPLE AND LLVM_VERSION VERSION_EQUAL 10.0.1 AND EXISTS "/usr/local/Cellar/llvm")
     message (WARNING
@@ -118,7 +118,7 @@ endif ()
 # Use opaque pointers starting with LLVM 16
 if (${LLVM_VERSION} VERSION_GREATER_EQUAL 16.0)
   set(LLVM_OPAQUE_POINTERS ON)
-  add_definitions (-DOSL_LLVM_OPAQUE_POINTERS)
+  add_compile_definitions (OSL_LLVM_OPAQUE_POINTERS)
 else()
   set(LLVM_OPAQUE_POINTERS OFF)
 endif()
@@ -126,7 +126,7 @@ endif()
 # Enable new pass manager for LLVM 16+
 if (${LLVM_VERSION} VERSION_GREATER_EQUAL 16.0)
   set(LLVM_NEW_PASS_MANAGER ON)
-  add_definitions (-DOSL_LLVM_NEW_PASS_MANAGER)
+  add_compile_definitions (OSL_LLVM_NEW_PASS_MANAGER)
 else()
   set(LLVM_NEW_PASS_MANAGER OFF)
 endif()
@@ -215,7 +215,7 @@ if (OSL_USE_OPTIX)
     function (osl_optix_target TARGET)
         target_include_directories (${TARGET} BEFORE PRIVATE ${CUDA_INCLUDES} ${OPTIX_INCLUDES})
         ## XXX: Should -DPTX_PATH point to (or include) CMAKE_CURRENT_BINARY_DIR so tests can run before installation ?
-        target_compile_definitions (${TARGET} PRIVATE "-DPTX_PATH=\"${OSL_PTX_INSTALL_DIR}\"")
+        target_compile_definitions (${TARGET} PRIVATE PTX_PATH="${OSL_PTX_INSTALL_DIR}")
         target_link_libraries (${TARGET} PRIVATE ${CUDA_LIBRARIES} ${CUDA_EXTRA_LIBS} ${OPTIX_LIBRARIES} ${OPTIX_EXTRA_LIBS})
     endfunction()
 else ()
diff --git a/src/cmake/flexbison.cmake b/src/cmake/flexbison.cmake
index 9959cfa58..0c9bb07dd 100644
--- a/src/cmake/flexbison.cmake
+++ b/src/cmake/flexbison.cmake
@@ -21,9 +21,14 @@
 # MacOS/xcode in /usr/bin, which seems to be too old for the reentrant
 # parser directives we use. Only do this if there is no BISON_ROOT
 # specifying a particular Bison to use.
-if (APPLE AND EXISTS /usr/local/opt
-        AND NOT BISON_ROOT AND NOT DEFINED ENV{BISON_ROOT})
-    find_program(BISON_EXECUTABLE NAMES /usr/local/opt/bison/bin/bison
+if (APPLE AND NOT BISON_ROOT AND NOT DEFINED ENV{BISON_ROOT}
+    AND (EXISTS /usr/local/opt OR EXISTS /opt/homebrew
+         OR DEFINED ENV{HOMEBREW_PREFIX}))
+    find_program(BISON_EXECUTABLE
+                 NAMES
+                    ENV{HOMEBREW_PREFIX}/opt/bison/bin/bison
+                    /opt/homebrew/opt/bison/bin/bison
+                    /usr/local/opt/bison/bin/bison
                  DOC "path to the bison executable")
 endif()
 
@@ -36,7 +41,7 @@ if ( FLEX_EXECUTABLE AND BISON_EXECUTABLE )
     macro ( FLEX_BISON flexsrc bisonsrc prefix srclist compiler_headers )
         # mangle osoparse & oslparse symbols to avoid multiple library conflicts
         # XXX: This may be excessive now that OSL::pvt::ExtraArg is mangled into the function signature
-        add_definitions(-D${prefix}parse=${PROJ_NAMESPACE_V}_${prefix}parse)
+        add_compile_definitions(${prefix}parse=${PROJ_NAMESPACE_V}_${prefix}parse)
 
         message (VERBOSE "FLEX_BISON flex=${flexsrc} bison=${bisonsrc} prefix=${prefix}")
         get_filename_component ( bisonsrc_we ${bisonsrc} NAME_WE )
diff --git a/src/cmake/modules/FindLLVM.cmake b/src/cmake/modules/FindLLVM.cmake
index 9cdaeed1c..967f32874 100644
--- a/src/cmake/modules/FindLLVM.cmake
+++ b/src/cmake/modules/FindLLVM.cmake
@@ -109,7 +109,7 @@ endif ()
 foreach (COMPONENT clangFrontend clangDriver clangSerialization
                    clangParse clangSema clangAnalysis clangAST
                    clangASTMatchers clangBasic clangEdit clangLex
-                   clangSupport)
+                   clangSupport clangAPINotes)
     find_library ( _CLANG_${COMPONENT}_LIBRARY
                   NAMES ${COMPONENT}
                   PATHS ${LLVM_LIB_DIR})
diff --git a/src/cmake/set_utils.cmake b/src/cmake/set_utils.cmake
new file mode 100644
index 000000000..1f86e7ef2
--- /dev/null
+++ b/src/cmake/set_utils.cmake
@@ -0,0 +1,123 @@
+# Copyright Contributors to the Open Shading Language project.
+# SPDX-License-Identifier: BSD-3-Clause
+# https://github.com/AcademySoftwareFoundation/OpenShadingLanguage
+
+
+# Set a variable to a value if it is not already defined.
+macro (set_if_not var value)
+    if (NOT DEFINED ${var})
+        set (${var} ${value})
+    endif ()
+endmacro ()
+
+
+# Set a variable to a `replacement`, replacing its previous value, but only if
+# `replacement` is non-empty.
+macro (set_replace_if_nonempty var replacement)
+    if (NOT "${replacement}" STREQUAL "")
+        set (${var} ${replacement})
+    endif ()
+endmacro ()
+
+
+
+# Set a cmake variable `var` from an environment variable, if it is not
+# already defined (or if the FORCE flag is used). By default, the env var is
+# the same name as `var`, but you can specify a different env var name with
+# the ENVVAR keyword. If the env var doesn't exist or is empty, and a DEFAULT
+# is supplied, assign the default to the variable instead.  If the VERBOSE
+# CMake variable is set, or if the VERBOSE flag to this function is used,
+# print a message.
+macro (set_from_env var)
+    cmake_parse_arguments(_sfe   # prefix
+        # noValueKeywords:
+        "VERBOSE;FORCE"
+        # singleValueKeywords:
+        "ENVVAR;DEFAULT;NAME"
+        # multiValueKeywords:
+        ""
+        # argsToParse:
+        ${ARGN})
+    if (NOT DEFINED ${var} OR _sfe_FORCE)
+        set_if_not (_sfe_ENVVAR ${var})
+        set_if_not (_sfe_NAME ${var})
+        if (DEFINED ENV{${_sfe_ENVVAR}} AND NOT "$ENV{${_sfe_ENVVAR}}" STREQUAL "")
+            set (${var} $ENV{${_sfe_ENVVAR}})
+            if (_sfe_VERBOSE OR VERBOSE)
+                message (VERBOSE "set ${_sfe_NAME} = $ENV{${_sfe_ENVVAR}} (from env)")
+            endif ()
+        elseif (DEFINED _sfe_DEFAULT)
+            set (${var} ${_sfe_DEFAULT})
+        endif ()
+    endif ()
+endmacro ()
+
+
+
+# Wrapper for CMake `set()` functionality with extensions:
+# - If an env variable of the same name exists, it overrides the default
+#   value.
+# - In verbose mode or if the optional VERBOSE argument is passed, print the
+#   value and whether it came from the env.
+# - CACHE optional token makes it a cache variable.
+# - ADVANCED optional token sets it as "mark_as_advanced" without the need
+#   for a separate call (only applies to cache variables.)
+# - FILEPATH, PATH, BOOL, STRING optional token works as usual (only applies
+#   to cache variables).
+# - `DOC <docstring>` specifies a doc string for cache variables. If omitted,
+#   an empty doc string will be used.
+# Other extensions may be added in the future.
+macro (super_set name value)
+    cmake_parse_arguments(_sce   # prefix
+        # noValueKeywords:
+        "FORCE;ADVANCED;FILEPATH;PATH;BOOL;STRING;CACHE;VERBOSE"
+        # singleValueKeywords:
+        "DOC"
+        # multiValueKeywords:
+        ""
+        # argsToParse:
+        ${ARGN})
+    set (_sce_extra_args "")
+    if (_sce_FILEPATH)
+        set (_sce_type "FILEPATH")
+    elseif (_sce_PATH)
+        set (_sce_type "PATH")
+    elseif (_sce_BOOL)
+        set (_sce_type "BOOL")
+    else ()
+        set (_sce_type "STRING")
+    endif ()
+    if (_sce_FORCE)
+        list (APPEND _sce_extra_args FORCE)
+    endif ()
+    set_if_not (_sce_DOC "empty")
+    set_from_env (_sce_val ENVVAR ${name} NAME ${name} DEFAULT ${value})
+    if (_sce_CACHE)
+        set (${name} ${_sce_val} CACHE ${_sce_type} "${_sce_DOC}" ${_sce_extra_args})
+    else ()
+        set (${name} ${_sce_val} ${_sce_extra_args})
+    endif ()
+    if (_sce_VERBOSE)
+        message (STATUS "${name} = ${${name}}")
+    else ()
+        message (VERBOSE "${name} = ${${name}}")
+    endif ()
+    if (_sce_ADVANCED)
+        mark_as_advanced (${name})
+    endif ()
+    unset (_sce_extra_args)
+    unset (_sce_type)
+    unset (_sce_val)
+endmacro ()
+
+
+# `set(... CACHE ...)` workalike using super_set underneath.
+macro (set_cache name value docstring)
+    super_set (${name} "${value}" DOC ${docstring} CACHE ${ARGN})
+endmacro ()
+
+
+# `option()` workalike using super_set underneath.
+macro (set_option name docstring value)
+    set_cache (${name} "${value}" ${docstring} BOOL ${ARGN})
+endmacro ()
diff --git a/src/cmake/testing.cmake b/src/cmake/testing.cmake
index fc5e956b0..9f37b3d6c 100644
--- a/src/cmake/testing.cmake
+++ b/src/cmake/testing.cmake
@@ -348,7 +348,7 @@ macro (osl_add_all_tests)
                 printf-reg
                 printf-whole-array
                 raytype raytype-reg raytype-specialized regex-reg
-                reparam reparam-arrays testoptix-reparam
+                reparam reparam-arrays reparam-string testoptix-reparam
                 render-background render-bumptest
                 render-cornell render-furnace-diffuse
                 render-mx-furnace-burley-diffuse
diff --git a/src/include/OSL/hashes.h b/src/include/OSL/hashes.h
index 7e0b65a09..1e91f36fc 100644
--- a/src/include/OSL/hashes.h
+++ b/src/include/OSL/hashes.h
@@ -40,7 +40,11 @@ constexpr inline size_t
 strhash(const char* s)
 {
     size_t len = pvt::pvtstrlen(s);
-    return OIIO::Strutil::strhash(OIIO::string_view(s, len));
+#ifdef OIIO_USTRING_SAFE_HASH
+    return ustring::strhash(string_view(s, len));
+#else
+    return OIIO::Strutil::strhash(string_view(s, len));
+#endif
 }
 
 // Template to ensure the hash is evaluated at compile time.
diff --git a/src/include/OSL/oslconfig.h.in b/src/include/OSL/oslconfig.h.in
index 612f13b58..4f0645d3a 100644
--- a/src/include/OSL/oslconfig.h.in
+++ b/src/include/OSL/oslconfig.h.in
@@ -248,19 +248,8 @@ enum class SymArena {
 // various C++ versions or compilers, or to make up for things not
 // yet available in earlier C++ standards.
 
-#if OSL_CPLUSPLUS_VERSION >= 17
-    // fold expression to expand
-    #define __OSL_EXPAND_PARAMETER_PACKS(EXPRESSION) \
-        (void((EXPRESSION)) , ... );
-#else
-    // Choose to use initializer list to expand our parameter pack so that
-    // the order they are evaluated in the order they appear
-    #define __OSL_EXPAND_PARAMETER_PACKS(EXPRESSION) \
-        { \
-            using expander = int [sizeof...(IntListT)]; \
-            (void)expander{((EXPRESSION),0)...}; \
-        }
-#endif
+// fold expression to expand
+#define __OSL_EXPAND_PARAMETER_PACKS(EXPRESSION) (void((EXPRESSION)), ...);
 
 
 namespace pvt {
@@ -271,26 +260,20 @@ using int_sequence = std::integer_sequence<int, IntegerListT...>;
 template<int EndBeforeT>
 using make_int_sequence =  std::make_integer_sequence<int, EndBeforeT>;
 
- template<bool... BoolListT >
-using bool_sequence = std::integer_sequence<bool, BoolListT... >;
+template<bool... BoolListT>
+using bool_sequence = std::integer_sequence<bool, BoolListT...>;
 
-#if (OSL_CPLUSPLUS_VERSION >= 17)
-    template<class... ListT>
-    using conjunction = std::conjunction<ListT...>;
-#else
-    template<class... ListT>
-    using conjunction = std::is_same<bool_sequence<true,ListT::value...>, bool_sequence<ListT::value..., true>>;
-#endif
+template<class... ListT> using conjunction = std::conjunction<ListT...>;
 
-    // We need the SFINAE type to be different for
-    // enable_if_type from disable_if_type so that we can apply both to
-    // the same template signature to avoid
-    // "error: invalid redeclaration of member function template"
-    // NOTE: std::enable_if_t is a c++14 library feature, our baseline
-    // and we wish to remain compatible with c++11 header libraries.
-    // Also we are using std::true_type vs. void as the default type
-    template <bool TestT, typename TypeT = std::true_type>
-    using enable_if_type = typename std::enable_if<TestT, TypeT>::type;
+// We need the SFINAE type to be different for
+// enable_if_type from disable_if_type so that we can apply both to
+// the same template signature to avoid
+// "error: invalid redeclaration of member function template"
+// NOTE: std::enable_if_t is a c++14 library feature, our baseline
+// and we wish to remain compatible with c++11 header libraries.
+// Also we are using std::true_type vs. void as the default type
+template<bool TestT, typename TypeT = std::true_type>
+using enable_if_type = typename std::enable_if<TestT, TypeT>::type;
 
 } // namespace pvt
 
diff --git a/src/include/OSL/oslexec.h b/src/include/OSL/oslexec.h
index 7583c7765..5e2220e51 100644
--- a/src/include/OSL/oslexec.h
+++ b/src/include/OSL/oslexec.h
@@ -1159,7 +1159,7 @@ shade_image(ShadingSystem& shadingsys, ShaderGroup& group,
             const ShaderGlobals* defaultsg, OIIO::ImageBuf& buf,
             cspan<ustring> outputs,
             ShadeImageLocations shadelocations = ShadePixelCenters,
-            OIIO::ROI roi = OIIO::ROI(), OIIO::parallel_options popt = 0);
+            OIIO::ROI roi = OIIO::ROI(), OIIO::paropt popt = 0);
 
 #endif
 
diff --git a/src/include/OSL/oslversion.h.in b/src/include/OSL/oslversion.h.in
index 11c605dc1..39186dadb 100644
--- a/src/include/OSL/oslversion.h.in
+++ b/src/include/OSL/oslversion.h.in
@@ -84,6 +84,7 @@ namespace @PROJ_NAME@ = @PROJ_NAMESPACE_V@;
 #define @PROJ_NAME@_BUILD_CPP14 (@CMAKE_CXX_STANDARD@ >= 14)
 #define @PROJ_NAME@_BUILD_CPP17 (@CMAKE_CXX_STANDARD@ >= 17)
 #define @PROJ_NAME@_BUILD_CPP20 (@CMAKE_CXX_STANDARD@ >= 20)
+#define @PROJ_NAME@_BUILD_CPP23 (@CMAKE_CXX_STANDARD@ >= 20)
 
 #define OSL_SHADER_INSTALL_DIR "@OSL_SHADER_INSTALL_DIR@"
 
diff --git a/src/include/OSL/platform.h b/src/include/OSL/platform.h
index c133ef89f..39fb4496c 100644
--- a/src/include/OSL/platform.h
+++ b/src/include/OSL/platform.h
@@ -113,6 +113,10 @@
 #  define OSL_MSVS_BEFORE_2015   (_MSC_VER <  1900)
 #  define OSL_MSVS_AT_LEAST_2017 (_MSC_VER >= 1910)
 #  define OSL_MSVS_BEFORE_2017   (_MSC_VER <  1910)
+#  define OSL_MSVS_AT_LEAST_2019 (_MSC_VER >= 1920)
+#  define OSL_MSVS_BEFORE_2019   (_MSC_VER <  1920)
+#  define OSL_MSVS_AT_LEAST_2022 (_MSC_VER >= 1930)
+#  define OSL_MSVS_BEFORE_2022   (_MSC_VER <  1930)
 #  if OSL_MSVS_BEFORE_2017
 #    error "This version of OSL is meant to work only with Visual Studio 2017 or later"
 #  endif
@@ -124,6 +128,10 @@
 #  define OSL_MSVS_BEFORE_2015   0
 #  define OSL_MSVS_AT_LEAST_2017 0
 #  define OSL_MSVS_BEFORE_2017   0
+#  define OSL_MSVS_AT_LEAST_2019 0
+#  define OSL_MSVS_BEFORE_2019   0
+#  define OSL_MSVS_AT_LEAST_2022 0
+#  define OSL_MSVS_BEFORE_2022   0
 #endif
 
 
@@ -132,31 +140,28 @@
 // Detect which C++ standard we're using, and handy macros.
 // See https://en.cppreference.com/w/cpp/compiler_support
 //
-// Note: oslversion.h defines OSL_BUILD_CPP to be 14, 17, etc., to reflect
+// Note: oslversion.h defines OSL_BUILD_CPP to be 17, 20, etc., to reflect
 // the version that OSL itself was built with. In contrast,
 // OSL_CPLUSPLUS_VERSION defined below will be set to the right number for
 // the C++ standard being compiled RIGHT NOW by whomever is parsing these
 // header files. These two things may be the same when compiling OSL, but
 // they may not be the same if another package is compiling against OSL and
-// using these headers (e.g., OSL may be C++14 but the client package may be
+// using these headers (e.g., OSL may be C++17 but the client package may be
 // newer, or vice versa -- use these two symbols to differentiate these
 // cases, when important).
 #if (__cplusplus >= 202001L)
 #    define OSL_CPLUSPLUS_VERSION 20
-#    define OSL_CONSTEXPR17 constexpr
 #    define OSL_CONSTEXPR20 constexpr
-#elif (__cplusplus >= 201703L)
+#elif (__cplusplus >= 201703L) || (defined(_MSC_VER) && _MSC_VER >= 1914)
 #    define OSL_CPLUSPLUS_VERSION 17
-#    define OSL_CONSTEXPR17 constexpr
-#    define OSL_CONSTEXPR20 /* not constexpr before C++20 */
-#elif (__cplusplus >= 201402L) || (defined(_MSC_VER) && _MSC_VER >= 1914)
-#    define OSL_CPLUSPLUS_VERSION 14
-#    define OSL_CONSTEXPR17 /* not constexpr before C++17 */
 #    define OSL_CONSTEXPR20 /* not constexpr before C++20 */
 #else
-#    error "This version of OSL requires C++14 or above"
+#    error "This version of OSL requires C++17 or above"
 #endif
 
+// DEPRECATED(1.14): use C++17 constexpr
+#define OSL_CONSTEXPR17 constexpr
+
 // DEPRECATED(1.12): use C++14 constexpr
 #define OSL_CONSTEXPR14 constexpr
 
@@ -339,13 +344,9 @@
 
 // OSL_MAYBE_UNUSED is a function or variable attribute that assures the
 // compiler that it's fine for the item to appear to be unused.
-#if OSL_CPLUSPLUS_VERSION >= 17 || __has_cpp_attribute(maybe_unused)
-#    define OSL_MAYBE_UNUSED [[maybe_unused]]
-#elif defined(__GNUC__) || defined(__clang__) || defined(__INTEL_COMPILER) || __has_attribute(unused)
-#    define OSL_MAYBE_UNUSED __attribute__((unused))
-#else
-#    define OSL_MAYBE_UNUSED
-#endif
+// Consider this deprecated (as of OSL 1.14, C++17 minimum), you should favor
+// C++17's [[maybe_unused]] attribute.
+#define OSL_MAYBE_UNUSED [[maybe_unused]]
 
 
 // Some compilers define a special intrinsic to use in conditionals that can
@@ -393,26 +394,18 @@
 
 
 // OSL_DEPRECATED before a function declaration marks it as deprecated in
-// a way that will generate compile warnings if it is called (but will
-// preserve linkage compatibility).
-#if OSL_CPLUSPLUS_VERSION >= 14 || __has_cpp_attribute(deprecated)
-#  define OSL_DEPRECATED(msg) [[deprecated(msg)]]
-#elif defined(__GNUC__) || defined(__clang__) || __has_attribute(deprecated)
-#  define OSL_DEPRECATED(msg) __attribute__((deprecated(msg)))
-#elif defined(_MSC_VER)
-#  define OSL_DEPRECATED(msg) __declspec(deprecated(msg))
-#else
-#  define OSL_DEPRECATED(msg)
-#endif
+// a way that will generate compile warnings if it is called. This should
+// itself be considered deprecated (as of OSL 1.14) and code should use
+// [[deprecated(msg)]] instead.
+#define OSL_DEPRECATED(msg) [[deprecated(msg)]]
+
 
 // OSL_FALLTHROUGH at the end of a `case` label's statements documents that
 // the switch statement case is intentionally falling through to the code for
 // the next case.
-#if OSL_CPLUSPLUS_VERSION >= 17 || __has_cpp_attribute(fallthrough)
-#    define OSL_FALLTHROUGH [[fallthrough]]
-#else
-#    define OSL_FALLTHROUGH
-#endif
+// Consider this deprecated (as of OSL 1.14), you should favor C++17's
+// [[fallthrough]] attribute.
+#define OSL_FALLTHROUGH [[fallthrough]]
 
 
 // OSL_NODISCARD following a function declaration documents that the
diff --git a/src/liboslexec/CMakeLists.txt b/src/liboslexec/CMakeLists.txt
index 2a2ea5c1b..e0744b7dd 100644
--- a/src/liboslexec/CMakeLists.txt
+++ b/src/liboslexec/CMakeLists.txt
@@ -211,7 +211,7 @@ if (USE_LLVM_BITCODE)
     EMBED_LLVM_BITCODE_IN_CPP ( "${rs_dependent_ops_srcs}" "_host_rs" "osl_llvm_compiled_rs_dependent_ops" lib_src "" "${include_dirs}")
 
     if (CUDA_FOUND)
-        add_definitions (-DOSL_LLVM_CUDA_BITCODE)
+        add_compile_definitions (OSL_LLVM_CUDA_BITCODE)
 
         # The shadeops are compiled to both LLVM bitcode and PTX, and embedded
         # in liboslexec in binary format. The bitcode is used to seed the LLVM
@@ -255,7 +255,7 @@ else ()
     # With MSVC/Mingw, we don't compile llvm_ops.cpp to LLVM bitcode, due
     # to clang being unable to compile MSVC C++ header files at this time.
     # Instead it is part of the regular build process.
-    add_definitions (-DOSL_LLVM_NO_BITCODE)
+    add_compile_definitions (OSL_LLVM_NO_BITCODE)
     set (lib_src ${lib_src} llvm_ops.cpp)
 endif ()
 
diff --git a/src/liboslexec/batched_llvm_gen.cpp b/src/liboslexec/batched_llvm_gen.cpp
index dacf4f0ba..f589d6a94 100644
--- a/src/liboslexec/batched_llvm_gen.cpp
+++ b/src/liboslexec/batched_llvm_gen.cpp
@@ -2929,7 +2929,8 @@ LLVMGEN(llvm_gen_filterwidth)
             }
 
             rop.ll.call_function(rop.build_name(func_spec),
-                                 { &args[0], argCount });
+                                 { &args[0],
+                                   cspan<llvm::Value*>::size_type(argCount) });
             // Don't have 2nd order derivs
             rop.llvm_zero_derivs(Result);
         }
@@ -6957,7 +6958,9 @@ LLVMGEN(llvm_gen_calculatenormal)
         args[arg_count++] = rop.ll.mask_as_int(rop.ll.current_mask());
         func_spec.mask();
     }
-    rop.ll.call_function(rop.build_name(func_spec), { &args[0], arg_count });
+    rop.ll.call_function(rop.build_name(func_spec),
+                         { &args[0],
+                           cspan<llvm::Value*>::size_type(arg_count) });
 
     if (Result.has_derivs())
         rop.llvm_zero_derivs(Result);
diff --git a/src/liboslexec/batched_llvm_instance.cpp b/src/liboslexec/batched_llvm_instance.cpp
index 218063786..f6f325bbb 100644
--- a/src/liboslexec/batched_llvm_instance.cpp
+++ b/src/liboslexec/batched_llvm_instance.cpp
@@ -200,7 +200,7 @@ struct CStrHash {
     OSL_FORCEINLINE size_t operator()(const char* str) const
     {
         OSL_DASSERT(str != nullptr);
-        return OIIO::Strutil::strhash(str);
+        return OSL::strhash(str);
     }
 };
 
diff --git a/src/liboslexec/runtimeoptimize.cpp b/src/liboslexec/runtimeoptimize.cpp
index ca8c8f6b2..8e91a9d08 100644
--- a/src/liboslexec/runtimeoptimize.cpp
+++ b/src/liboslexec/runtimeoptimize.cpp
@@ -3290,7 +3290,13 @@ RuntimeOptimizer::run()
                 offset = OIIO::round_to_multiple_of_pow2(offset, alignment);
                 interactive_data.resize(offset + totalsize);
                 // Copy from the instance value to the interactive block
-                memcpy(&interactive_data[offset], s.data(), typesize);
+                // If the value is a string, copy its hash.
+                if (s.typespec().is_string()) {
+                    ustring string_data = *reinterpret_cast<ustring*>(s.data());
+                    ustringhash string_hash(string_data);
+                    memcpy(&interactive_data[offset], &string_hash, typesize);
+                } else
+                    memcpy(&interactive_data[offset], s.data(), typesize);
                 if (totalsize > typesize)
                     memset(&interactive_data[offset] + typesize, 0,
                            totalsize - typesize);
diff --git a/src/liboslexec/shadeimage.cpp b/src/liboslexec/shadeimage.cpp
index a556def54..247a74459 100644
--- a/src/liboslexec/shadeimage.cpp
+++ b/src/liboslexec/shadeimage.cpp
@@ -26,7 +26,7 @@ bool
 shade_image(ShadingSystem& shadingsys, ShaderGroup& group,
             const ShaderGlobals* defaultsg, OIIO::ImageBuf& buf,
             cspan<ustring> outputs, ShadeImageLocations shadelocations,
-            OIIO::ROI roi, OIIO::parallel_options popt)
+            OIIO::ROI roi, OIIO::paropt popt)
 {
     using namespace OIIO;
     using namespace ImageBufAlgo;
@@ -173,4 +173,16 @@ shade_image(ShadingSystem& shadingsys, ShaderGroup& group,
 
 
 
+// DEPRECATED(1.14)
+OSLEXECPUBLIC
+bool
+shade_image(ShadingSystem& shadingsys, ShaderGroup& group,
+            const ShaderGlobals* defaultsg, OIIO::ImageBuf& buf,
+            cspan<ustring> outputs, ShadeImageLocations shadelocations,
+            OIIO::ROI roi, OIIO::parallel_options popt)
+{
+    return shade_image(shadingsys, group, defaultsg, buf, outputs,
+                       shadelocations, roi, OIIO::paropt(popt));
+}
+
 OSL_NAMESPACE_EXIT
diff --git a/src/liboslexec/shadingsys.cpp b/src/liboslexec/shadingsys.cpp
index c0afc98f1..f238db2c5 100644
--- a/src/liboslexec/shadingsys.cpp
+++ b/src/liboslexec/shadingsys.cpp
@@ -3423,12 +3423,22 @@ ShadingSystemImpl::ReParameter(ShaderGroup& group, string_view layername_,
     size_t size = type.size();
     m_stat_reparam_calls_total += 1;
     m_stat_reparam_bytes_total += size;
-    if (memcmp(group.interactive_arena_ptr() + offset, val, size)) {
-        memcpy(group.interactive_arena_ptr() + offset, val, type.size());
+
+    // Copy ustringhashes instead of ustrings
+    const void* payload;
+    ustringhash string_hash;
+    if (type == TypeDesc::STRING) {
+        string_hash = ustringhash_from(*reinterpret_cast<const ustring*>(val));
+        payload     = &string_hash;
+    } else
+        payload = val;
+
+    if (memcmp(group.interactive_arena_ptr() + offset, payload, size)) {
+        memcpy(group.interactive_arena_ptr() + offset, payload, type.size());
         if (use_optix())
             renderer()->copy_to_device(group.device_interactive_arena().d_get()
                                            + offset,
-                                       val, type.size());
+                                       payload, type.size());
         m_stat_reparam_calls_changed += 1;
         m_stat_reparam_bytes_changed += size;
     }
diff --git a/src/liboslexec/wide/wide_optexture.cpp b/src/liboslexec/wide/wide_optexture.cpp
index 63353be22..2f99d6af8 100644
--- a/src/liboslexec/wide/wide_optexture.cpp
+++ b/src/liboslexec/wide/wide_optexture.cpp
@@ -117,14 +117,6 @@ default_texture(BatchedRendererServices* bsr, ustring filename,
             has_derivs ? (float*)&dresultds_simd : NULL,
             has_derivs ? (float*)&dresultdt_simd : NULL);
 
-        OIIO::simd::vfloat4 dresultdx_simd;
-        OIIO::simd::vfloat4 dresultdy_simd;
-        if (has_derivs) {
-            // Correct our st texture space gradients into xy-space gradients
-            dresultdx_simd = dresultds_simd * dsdx + dresultdt_simd * dtdx;
-            dresultdy_simd = dresultds_simd * dsdy + dresultdt_simd * dtdy;
-        }
-
         // NOTE: regardless of the value of "retVal" we will always copy over the texture system's results.
         // We are relying on the texture system properly filling in missing or fill colors
 
@@ -142,10 +134,10 @@ default_texture(BatchedRendererServices* bsr, ustring filename,
                 MaskedDx<Color3> resultDx(resultRef);
                 MaskedDy<Color3> resultDy(resultRef);
 
-                resultDx[lane] = Color3(dresultdx_simd[0], dresultdx_simd[1],
-                                        dresultdx_simd[2]);
-                resultDy[lane] = Color3(dresultdy_simd[0], dresultdy_simd[1],
-                                        dresultdy_simd[2]);
+                resultDx[lane] = Color3(dresultds_simd[0], dresultds_simd[1],
+                                        dresultds_simd[2]);
+                resultDy[lane] = Color3(dresultdt_simd[0], dresultdt_simd[1],
+                                        dresultdt_simd[2]);
             }
         } else if (Masked<float>::is(resultRef)) {
             alphaChannelIndex = 1;
@@ -154,8 +146,8 @@ default_texture(BatchedRendererServices* bsr, ustring filename,
             MaskedDy<float> resultDy(resultRef);
             result[lane] = result_simd[0];
             if (resultRef.has_derivs()) {
-                resultDx[lane] = dresultdx_simd[0];
-                resultDy[lane] = dresultdy_simd[0];
+                resultDx[lane] = dresultds_simd[0];
+                resultDy[lane] = dresultdt_simd[0];
             }
         }
 
@@ -165,8 +157,8 @@ default_texture(BatchedRendererServices* bsr, ustring filename,
             if (alphaRef.has_derivs()) {
                 MaskedDx<float> alphaDx(alphaRef);
                 MaskedDy<float> alphaDy(alphaRef);
-                alphaDx[lane] = dresultdx_simd[alphaChannelIndex];
-                alphaDy[lane] = dresultdy_simd[alphaChannelIndex];
+                alphaDx[lane] = dresultds_simd[alphaChannelIndex];
+                alphaDy[lane] = dresultdt_simd[alphaChannelIndex];
             }
         }
         //std::cout << "s: " << s.get(i) << " t: " << t.get(i) << " color: " << resultColor << " " << wideResult.get(i) << std::endl;
@@ -311,16 +303,6 @@ default_texture3d(BatchedRendererServices* bsr, ustring filename,
             has_derivs ? (float*)&dresultdt_simd : nullptr,
             has_derivs ? (float*)&dresultdr_simd : nullptr);
 
-        OIIO::simd::vfloat4 dresultdx_simd;
-        OIIO::simd::vfloat4 dresultdy_simd;
-        if (has_derivs) {
-            // Correct our str texture space gradients into xyz-space gradients
-            dresultdx_simd = dresultds_simd * dPdx.x + dresultdt_simd * dPdx.y
-                             + dresultdr_simd * dPdx.z;
-            dresultdy_simd = dresultds_simd * dPdy.x + dresultdt_simd * dPdy.y
-                             + dresultdr_simd * dPdy.z;
-        }
-
         // NOTE: regardless of the value of "retVal" we will always copy over the texture system's results.
         // We are relying on the texture system properly filling in missing or fill colors
 
@@ -337,10 +319,10 @@ default_texture3d(BatchedRendererServices* bsr, ustring filename,
             if (resultRef.has_derivs()) {
                 MaskedDx<Color3> resultDx(resultRef);
                 MaskedDy<Color3> resultDy(resultRef);
-                resultDx[lane] = Color3(dresultdx_simd[0], dresultdx_simd[1],
-                                        dresultdx_simd[2]);
-                resultDy[lane] = Color3(dresultdy_simd[0], dresultdy_simd[1],
-                                        dresultdy_simd[2]);
+                resultDx[lane] = Color3(dresultds_simd[0], dresultds_simd[1],
+                                        dresultds_simd[2]);
+                resultDy[lane] = Color3(dresultdt_simd[0], dresultdt_simd[1],
+                                        dresultdt_simd[2]);
             }
         } else if (Masked<float>::is(resultRef)) {
             alphaChannelIndex = 1;
@@ -349,8 +331,8 @@ default_texture3d(BatchedRendererServices* bsr, ustring filename,
             if (resultRef.has_derivs()) {
                 MaskedDx<float> resultDx(resultRef);
                 MaskedDy<float> resultDy(resultRef);
-                resultDx[lane] = dresultdx_simd[0];
-                resultDy[lane] = dresultdy_simd[0];
+                resultDx[lane] = dresultds_simd[0];
+                resultDy[lane] = dresultdt_simd[0];
             }
         }
 
@@ -361,8 +343,8 @@ default_texture3d(BatchedRendererServices* bsr, ustring filename,
             if (alphaRef.has_derivs()) {
                 MaskedDx<float> alphaDx(alphaRef);
                 MaskedDy<float> alphaDy(alphaRef);
-                alphaDx[lane] = dresultdx_simd[alphaChannelIndex];
-                alphaDy[lane] = dresultdy_simd[alphaChannelIndex];
+                alphaDx[lane] = dresultds_simd[alphaChannelIndex];
+                alphaDy[lane] = dresultdt_simd[alphaChannelIndex];
             }
         }
 
@@ -561,6 +543,164 @@ dispatch_environment(BatchedRendererServices* bsr, ustring filename,
 }  // namespace
 
 
+static OSL_NOINLINE void
+transformWideTextureGradients(BatchedTextureOutputs& outputs,
+                              Wide<const float> dsdx, Wide<const float> dtdx,
+                              Wide<const float> dsdy, Wide<const float> dtdy)
+{
+    MaskedData resultRef = outputs.result();
+    if (resultRef.valid() && resultRef.has_derivs()) {
+        if (Masked<float>::is(resultRef)) {
+            OSL_FORCEINLINE_BLOCK
+            {
+                MaskedDx<float> drds(resultRef);
+                MaskedDy<float> drdt(resultRef);
+
+                OSL_OMP_PRAGMA(omp simd simdlen(__OSL_WIDTH))
+                for (int i = 0; i < __OSL_WIDTH; ++i) {
+                    float drdsVal = drds[i];
+                    float drdtVal = drdt[i];
+                    float drdx    = drdsVal * dsdx[i] + drdtVal * dtdx[i];
+                    float drdy    = drdsVal * dsdy[i] + drdtVal * dtdy[i];
+                    drds[i]       = drdx;
+                    drdt[i]       = drdy;
+                }
+            }
+        } else {
+            // keep assert out of inlined code
+            OSL_DASSERT(Masked<Color3>::is(resultRef));
+            OSL_FORCEINLINE_BLOCK
+            {
+                //printf("doint color\n");
+                MaskedDx<Color3> widedrds(resultRef);
+                MaskedDy<Color3> widedrdt(resultRef);
+                OSL_OMP_PRAGMA(omp simd simdlen(__OSL_WIDTH))
+                for (int i = 0; i < __OSL_WIDTH; ++i) {
+                    Color3 drdsColor = widedrds[i];
+                    Color3 drdtColor = widedrdt[i];
+
+                    widedrds[i] = drdsColor * dsdx[i] + drdtColor * dtdx[i];
+                    widedrdt[i] = drdsColor * dsdy[i] + drdtColor * dtdy[i];
+                }
+            }
+        }
+    }
+
+    MaskedData alphaRef = outputs.alpha();
+    OSL_FORCEINLINE_BLOCK
+    if (alphaRef.valid() && alphaRef.has_derivs()) {
+        MaskedDx<float> dads(alphaRef);
+        MaskedDy<float> dadt(alphaRef);
+        OSL_OMP_PRAGMA(omp simd simdlen(__OSL_WIDTH))
+        for (int i = 0; i < __OSL_WIDTH; ++i) {
+            float dadsVal = dads[i];
+            float dadtVal = dadt[i];
+            float dadx    = dadsVal * dsdx[i] + dadtVal * dtdx[i];
+            float dady    = dadsVal * dsdy[i] + dadtVal * dtdy[i];
+            dads[i]       = dadx;
+            dadt[i]       = dady;
+        }
+    }
+}
+
+static OSL_NOINLINE void
+transformWideTextureGradientsTexture3d(BatchedTextureOutputs& outputs,
+                                       Wide<const Vec3> Pdx,
+                                       Wide<const Vec3> Pdy,
+                                       Wide<const Vec3> Pdz)
+{
+    MaskedData resultRef = outputs.result();
+    if (resultRef.valid() && resultRef.has_derivs()) {
+        if (Masked<float>::is(resultRef)) {
+            OSL_FORCEINLINE_BLOCK
+            {
+                MaskedDx<float> drds(resultRef);
+                MaskedDy<float> drdt(resultRef);
+                //MaskedDz<float> drdr(resultRef); // our duals don't actually have space for this
+
+                OSL_OMP_PRAGMA(omp simd simdlen(__OSL_WIDTH))
+                for (int i = 0; i < __OSL_WIDTH; ++i) {
+                    float dres_xVal = drds[i];
+                    float dres_yVal = drdt[i];
+                    //float dres_zVal = drdr[i];
+
+                    Vec3 v3pdx = Pdx[i];
+                    Vec3 v3pdy = Pdy[i];
+                    //Vec3 v3pdz = Pdz[i];
+
+                    float dres_x = dres_xVal * v3pdx.x
+                                   + dres_yVal
+                                         * v3pdx.y;  // + dres_zVal * v3pdx.z;
+                    float dres_y = dres_xVal * v3pdy.x
+                                   + dres_yVal
+                                         * v3pdy.y;  // + dres_zVal * v3pdy.z;
+                    //float dres_z = dres_xVal * v3pdz.x + dres_yVal * v3pdz.y + dres_zVal * v3pdz.z;
+
+                    drds[i] = dres_x;
+                    drdt[i] = dres_y;
+                    //drdr[i] = dres_z;
+                }
+            }
+        } else {
+            // keep assert out of inlined code
+            OSL_DASSERT(Masked<Color3>::is(resultRef));
+            OSL_FORCEINLINE_BLOCK
+            {
+                MaskedDx<Color3> widedrp1(resultRef);
+                MaskedDy<Color3> widedrp2(resultRef);
+                //MaskedDz<Color3> widedrp3(resultRef);
+
+                OSL_OMP_PRAGMA(omp simd simdlen(__OSL_WIDTH))
+                for (int i = 0; i < __OSL_WIDTH; ++i) {
+                    Color3 drdp1Color = widedrp1[i];
+                    Color3 drdp2Color = widedrp2[i];
+                    //Color3 drdp3Color = widedrp3[i];
+
+                    Vec3 v3pdx = Pdx[i];
+                    Vec3 v3pdy = Pdy[i];
+                    //Vec3 v3pdz = Pdz[i];
+
+                    widedrp1[i] = drdp1Color * v3pdx.x
+                                  + drdp2Color
+                                        * v3pdx.y;  // + drdp3Color * v3pdx.z;
+                    widedrp2[i] = drdp1Color * v3pdy.x
+                                  + drdp2Color
+                                        * v3pdy.y;  // + drdp3Color * v3pdy.z;
+                    //widedrp3[i] = drdp1Color * v3pdz.x +  drdp2Color * v3pdz.y + drdp3Color * v3pdz.z;
+                }
+            }
+        }
+    }
+
+    MaskedData alphaRef = outputs.alpha();
+    OSL_FORCEINLINE_BLOCK
+    if (alphaRef.valid() && alphaRef.has_derivs()) {
+        MaskedDx<float> dap1(alphaRef);
+        MaskedDy<float> dap2(alphaRef);
+        // MaskedDz<float> dap3(alphaRef);
+
+        OSL_OMP_PRAGMA(omp simd simdlen(__OSL_WIDTH))
+        for (int i = 0; i < __OSL_WIDTH; ++i) {
+            float dadp1Val = dap1[i];
+            float dadp2Val = dap2[i];
+            //float dadp3Val = dap3[i];
+
+            Vec3 v3pdx = Pdx[i];
+            Vec3 v3pdy = Pdy[i];
+            //Vec3 v3pdz = Pdz[i];
+
+            float dadpx = dadp1Val * v3pdx.x
+                          + dadp2Val * v3pdx.y;  // + dadp3Val * v3pdx.z;
+            float dadpy = dadp1Val * v3pdy.x
+                          + dadp2Val * v3pdy.y;  // + dadp3Val * v3pdy.z;
+            //float dadpz = dadp1Val * v3pdz.x + dadp2Val * v3pdz.y + dadp3Val * v3pdz.z;
+
+            dap1[i] = dadpx;
+            dap2[i] = dadpy;
+            //dap3[i] = dadpz;
+        }
+    }
+}
 
 OSL_BATCHOP int
 __OSL_MASKED_OP(texture)(void* bsg_, ustring_pod name_, void* handle,
@@ -590,6 +730,14 @@ __OSL_MASKED_OP(texture)(void* bsg_, ustring_pod name_, void* handle,
                            Wide<const float>(dsdy), Wide<const float>(dtdy),
                            outputs);
 
+    // Correct our st texture space gradients into xy-space gradients
+    if (resultHasDerivs || alphaHasDerivs) {
+        transformWideTextureGradients(outputs, Wide<const float>(dsdx),
+                                      Wide<const float>(dtdx),
+                                      Wide<const float>(dsdy),
+                                      Wide<const float>(dtdy));
+    }
+
     OSL_FORCEINLINE_BLOCK
     if (outputs.errormessage().valid()) {
         Masked<ustring> err(outputs.errormessage());
@@ -637,6 +785,13 @@ __OSL_MASKED_OP(texture3d)(void* bsg_, ustring_pod name_, void* handle,
                              Wide<const Vec3>(wPdy), Wide<const Vec3>(wPdz),
                              outputs);
 
+    // Correct our P (Vec3) space gradients into xyz-space gradients
+    if (resultHasDerivs || alphaHasDerivs) {
+        transformWideTextureGradientsTexture3d(outputs, Wide<const Vec3>(wPdx),
+                                               Wide<const Vec3>(wPdy),
+                                               Wide<const Vec3>(wPdz));
+    }
+
     OSL_FORCEINLINE_BLOCK
     if (outputs.errormessage().valid()) {
         Masked<ustring> err(outputs.errormessage());
diff --git a/src/osl.imageio/oslinput.cpp b/src/osl.imageio/oslinput.cpp
index 0ca136eb0..2c932b082 100644
--- a/src/osl.imageio/oslinput.cpp
+++ b/src/osl.imageio/oslinput.cpp
@@ -59,29 +59,29 @@ OSL_NAMESPACE_ENTER
 class OSLInput final : public ImageInput {
 public:
     OSLInput();
-    virtual ~OSLInput();
-    virtual const char* format_name(void) const { return "osl"; }
-    virtual int supports(string_view feature) const
+    virtual ~OSLInput() override;
+    virtual const char* format_name(void) const override { return "osl"; }
+    virtual int supports(string_view feature) const override
     {
         return (feature == "procedural");
     }
-    virtual bool valid_file(const std::string& filename) const;
-    virtual bool open(const std::string& name, ImageSpec& newspec);
+    virtual bool valid_file(const std::string& filename) const override;
+    virtual bool open(const std::string& name, ImageSpec& newspec) override;
     virtual bool open(const std::string& name, ImageSpec& newspec,
-                      const ImageSpec& config);
-    virtual bool close();
-    virtual int current_subimage(void) const { return m_subimage; }
-    virtual int current_miplevel(void) const { return m_miplevel; }
-    virtual bool seek_subimage(int subimage, int miplevel);
+                      const ImageSpec& config) override;
+    virtual bool close() override;
+    virtual int current_subimage(void) const override { return m_subimage; }
+    virtual int current_miplevel(void) const override { return m_miplevel; }
+    virtual bool seek_subimage(int subimage, int miplevel) override;
     virtual bool read_native_scanline(int subimage, int miplevel, int y, int z,
-                                      void* data);
+                                      void* data) override;
     virtual bool read_native_scanlines(int subimage, int miplevel, int ybegin,
-                                       int yend, int z, void* data);
+                                       int yend, int z, void* data) override;
     virtual bool read_native_tile(int subimage, int miplevel, int x, int y,
-                                  int z, void* data);
+                                  int z, void* data) override;
     virtual bool read_native_tiles(int subimage, int miplevel, int xbegin,
                                    int xend, int ybegin, int yend, int zbegin,
-                                   int zend, void* data);
+                                   int zend, void* data) override;
 
 private:
     std::string m_filename;  ///< Stash the filename
@@ -112,14 +112,14 @@ osl_input_imageio_create()
     return new OSLInput;
 }
 
-OIIO_EXPORT void
-osl_input_imageio_delete(ImageInput* p)
+OIIO_EXPORT int osl_imageio_version = OIIO_PLUGIN_VERSION;
+
+OIIO_EXPORT const char*
+osl_imageio_library_version()
 {
-    delete p;
+    return ustring(OSL_LIBRARY_VERSION_STRING).c_str();
 }
 
-OIIO_EXPORT int osl_imageio_version = OIIO_PLUGIN_VERSION;
-
 OIIO_EXPORT const char* osl_input_extensions[] = { "osl", "oso", "oslgroup",
                                                    "oslbody", NULL };
 
@@ -498,14 +498,13 @@ OSLInput::open(const std::string& name, ImageSpec& newspec,
         OIIO::lock_guard lock(shading_mutex);
         shadername.remove_suffix(4);
         m_group = shadingsys->ShaderGroupBegin();
-        for (size_t p = 0, np = m_topspec.extra_attribs.size(); p < np; ++p) {
-            const ParamValue& pv(m_topspec.extra_attribs[p]);
+        for (auto&& pv : m_topspec.extra_attribs) {
             shadingsys->Parameter(pv.name(), pv.type(), pv.data(),
                                   pv.interp() == ParamValue::INTERP_CONSTANT);
         }
         if (!shadingsys->Shader("surface", shadername, "" /*layername*/)) {
-            errorfmt("y {}", errhandler.haserror() ? errhandler.geterror()
-                                                   : std::string("OSL error"));
+            errorfmt("{}", errhandler.haserror() ? errhandler.geterror()
+                                                 : std::string("OSL error"));
             ok = false;
         }
         shadingsys->ShaderGroupEnd();
@@ -605,11 +604,7 @@ bool
 OSLInput::read_native_scanlines(int subimage, int miplevel, int ybegin,
                                 int yend, int z, void* data)
 {
-#if OIIO_PLUGIN_VERSION >= 24
     lock_guard lock(*this);
-#else
-    lock_guard lock(m_mutex);
-#endif
     if (!seek_subimage(subimage, miplevel))
         return false;
 
@@ -650,20 +645,16 @@ OSLInput::read_native_tiles(int subimage, int miplevel, int xbegin, int xend,
                             int ybegin, int yend, int zbegin, int zend,
                             void* data)
 {
-#if OIIO_PLUGIN_VERSION >= 24
     lock_guard lock(*this);
-#else
-    lock_guard lock(m_mutex);
-#endif
     if (!seek_subimage(subimage, miplevel))
         return false;
     if (!m_group.get()) {
-        errorfmt("read_native_scanlines called with missing shading group");
+        errorfmt("read_native_tiles called with missing shading group");
         return false;
     }
 
     // Create an ImageBuf wrapper of the user's data
-    ImageSpec spec = m_spec;  // Make a spec that describes just this scanline
+    ImageSpec spec = m_spec;  // Make a spec that describes just these tiles
     spec.x         = xbegin;
     spec.y         = ybegin;
     spec.z         = zbegin;
diff --git a/src/osltoy/osltoyapp.cpp b/src/osltoy/osltoyapp.cpp
index aa47d639f..3e6a59d08 100644
--- a/src/osltoy/osltoyapp.cpp
+++ b/src/osltoy/osltoyapp.cpp
@@ -432,9 +432,8 @@ OSLToyMainWindow::OSLToyMainWindow(OSLToyRenderer* rend, int xr, int yr)
     QPixmap pixmap(xres, yres);
     OIIO::ImageBuf checks(
         OIIO::ImageSpec(xres, yres, 3, OIIO::TypeDesc::UINT8));
-    const float white[] = { 1, 1, 1 };
-    const float black[] = { 0, 0, 0 };
-    OIIO::ImageBufAlgo::checker(checks, 16, 16, 1, white, black);
+    OIIO::ImageBufAlgo::checker(checks, 16, 16, 1, 1.0f /* white */,
+                                0.0f /* black */);
     renderView->update(checks);
 
     textTabs = new QTabWidget;
diff --git a/src/osltoy/osltoyrenderer.cpp b/src/osltoy/osltoyrenderer.cpp
index f4584810c..968021d48 100644
--- a/src/osltoy/osltoyrenderer.cpp
+++ b/src/osltoy/osltoyrenderer.cpp
@@ -130,11 +130,7 @@ OSLToyRenderer::render_image()
             OIIO::ImageSpec(m_xres, m_yres, 3, TypeDesc::FLOAT));
 
     static ustring outputs[] = { ustring("Cout") };
-    //    OIIO::Timer timer;
-    OIIO::parallel_options popt;
-    popt.minitems  = 4096;
-    popt.splitdir  = OIIO::Split_Tile;
-    popt.recursive = true;
+    OIIO::paropt popt(0, OIIO::paropt::SplitDir::Tile, 4096);
     shade_image(*shadingsys(), *shadergroup(), &m_shaderglobals_template,
                 m_framebuffer, outputs, ShadePixelCenters, OIIO::ROI(), popt);
     //    std::cout << timer() << "\n";
diff --git a/src/osltoy/qtutils.h b/src/osltoy/qtutils.h
index a611aa339..709a7754c 100644
--- a/src/osltoy/qtutils.h
+++ b/src/osltoy/qtutils.h
@@ -105,7 +105,7 @@ ImageBuf_to_QImage(const OIIO::ImageBuf& ib)
         return {};
 
     if (ib.cachedpixels())
-        const_cast<ImageBuf*>(&ib)->make_writeable(true);
+        const_cast<ImageBuf*>(&ib)->make_writable(true);
     return QImage((const uchar*)ib.localpixels(), spec.width, spec.height,
                   (int)spec.scanline_bytes(), format);
 }
diff --git a/src/testrender/CMakeLists.txt b/src/testrender/CMakeLists.txt
index 5f72bfbdb..c48808f92 100644
--- a/src/testrender/CMakeLists.txt
+++ b/src/testrender/CMakeLists.txt
@@ -33,7 +33,7 @@ if (OSL_USE_OPTIX)
     endforeach ()
 
     # Compile the renderer-supplied shadeops (rend_lib) to LLVM bitcode and PTX
-    add_definitions (-DOSL_LLVM_CUDA_BITCODE)
+    add_compile_definitions (OSL_LLVM_CUDA_BITCODE)
     CUDA_SHADEOPS_COMPILE ( "rend_lib_testrender"
         rend_lib_bc
         rend_lib_ptx
diff --git a/src/testshade/CMakeLists.txt b/src/testshade/CMakeLists.txt
index 88d710166..cecc1b85e 100644
--- a/src/testshade/CMakeLists.txt
+++ b/src/testshade/CMakeLists.txt
@@ -38,7 +38,7 @@ if (OSL_USE_OPTIX)
     endforeach ()
 
     # Compile the renderer-supplied shadeops (rend_lib) to LLVM bitcode and PTX
-    add_definitions (-DOSL_LLVM_CUDA_BITCODE)
+    add_compile_definitions (OSL_LLVM_CUDA_BITCODE)
     CUDA_SHADEOPS_COMPILE ( "rend_lib_testshade"
         rend_lib_bc
         rend_lib_ptx
diff --git a/src/testshade/testshade.cpp b/src/testshade/testshade.cpp
index d8b6f749c..55244218f 100644
--- a/src/testshade/testshade.cpp
+++ b/src/testshade/testshade.cpp
@@ -1423,9 +1423,9 @@ batched_save_outputs(SimpleRenderer* rend, ShadingSystem* shadingsys,
                     int y    = by[batchIndex];
                     int data = batchResults[batchIndex];
                     float pixel[1];
-                    OIIO::convert_types(TypeDesc::BASETYPE(t.basetype), &data,
-                                        TypeDesc::FLOAT, &pixel[0],
-                                        1 /*nchans*/);
+                    OIIO::convert_pixel_values(TypeDesc::BASETYPE(t.basetype),
+                                               &data, TypeDesc::FLOAT,
+                                               &pixel[0], 1 /*nchans*/);
                     outputimg->setpixel(x, y, &pixel[0]);
                     if (print_outputs) {
                         *oStreams[batchIndex]
@@ -1447,9 +1447,9 @@ batched_save_outputs(SimpleRenderer* rend, ShadingSystem* shadingsys,
                         intPixel[c] = batchResults[batchIndex][c];
                     }
 
-                    OIIO::convert_types(TypeDesc::BASETYPE(t.basetype),
-                                        intPixel, TypeDesc::FLOAT, floatPixel,
-                                        3 /*nchans*/);
+                    OIIO::convert_pixel_values(TypeDesc::BASETYPE(t.basetype),
+                                               intPixel, TypeDesc::FLOAT,
+                                               floatPixel, 3 /*nchans*/);
                     outputimg->setpixel(x, y, floatPixel);
                     if (print_outputs) {
                         (*oStreams[batchIndex])
diff --git a/testsuite/example-batched-deformer/CMakeLists.txt b/testsuite/example-batched-deformer/CMakeLists.txt
index 75819d574..e14943365 100644
--- a/testsuite/example-batched-deformer/CMakeLists.txt
+++ b/testsuite/example-batched-deformer/CMakeLists.txt
@@ -2,15 +2,13 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # https://github.com/AcademySoftwareFoundation/OpenShadingLanguage
 
-cmake_minimum_required (VERSION 3.12)
+cmake_minimum_required (VERSION 3.15)
 project (oslbatcheddeformer
          LANGUAGES CXX)
 
 if (NOT CMAKE_BUILD_TYPE)
-    #set (CMAKE_BUILD_TYPE "Release")
-    set (CMAKE_BUILD_TYPE "Debug")
+    set (CMAKE_BUILD_TYPE "Release")
 endif ()
-set (CMAKE_BUILD_TYPE "Debug")
 
 message (STATUS "Building ${PROJECT_NAME} ${PROJECT_VERSION} - ${CMAKE_BUILD_TYPE}")
 
@@ -20,7 +18,7 @@ set (CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
 set (CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
 
 # Use C++11
-set (CMAKE_CXX_STANDARD 14 CACHE STRING "C++ standard to prefer (14, 17, 20, etc.)")
+set (CMAKE_CXX_STANDARD 17 CACHE STRING "C++ standard to prefer (17, 20, etc.)")
 set (CMAKE_CXX_STANDARD_REQUIRED ON)
 set (CMAKE_CXX_EXTENSIONS OFF)
 
diff --git a/testsuite/example-cuda/CMakeLists.txt b/testsuite/example-cuda/CMakeLists.txt
index 11b0e369c..62986d0ce 100644
--- a/testsuite/example-cuda/CMakeLists.txt
+++ b/testsuite/example-cuda/CMakeLists.txt
@@ -2,7 +2,7 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # https://github.com/AcademySoftwareFoundation/OpenShadingLanguage
 
-cmake_minimum_required(VERSION 3.12)
+cmake_minimum_required(VERSION 3.15)
 project(examplecuda LANGUAGES CXX)
 
 if (NOT CMAKE_BUILD_TYPE)
@@ -38,8 +38,8 @@ find_library(CUDA_cuda_LIBRARY cuda HINTS ${CUDA_TOOLKIT_ROOT_DIR} PATH_SUFFIXES
 # TODO: move to sm_60?
 set(CUDA_TARGET_ARCH sm_35)
 
-set (CMAKE_CXX_STANDARD 14 CACHE STRING
-     "C++ standard to build with (14, 17, 20, etc.)")
+set (CMAKE_CXX_STANDARD 17 CACHE STRING
+     "C++ standard to build with (17, 20, etc.)")
 
 # Compile our "renderer" to PTX
 cuda_compile_ptx(CUDA_PTX_FILES cuda_grid_renderer.cu
@@ -84,6 +84,6 @@ add_executable(example-cuda example-cuda.cpp cuda_grid_renderer.cpp)
 
 target_link_libraries(example-cuda PRIVATE OSL::oslexec OSL::oslquery ${CUDA_LIBRARIES} ${CUDA_nvrtc_LIBRARY} ${CUDA_cuda_LIBRARY})
 target_include_directories(example-cuda PRIVATE ${CUDA_INCLUDE_DIRS})
-set_property(TARGET example-cuda PROPERTY CXX_STANDARD 14)
+set_property(TARGET example-cuda PROPERTY CXX_STANDARD 17)
 
 install(TARGETS example-cuda DESTINATION ${CMAKE_CURRENT_SOURCE_DIR})
diff --git a/testsuite/example-deformer/CMakeLists.txt b/testsuite/example-deformer/CMakeLists.txt
index 23a6550cb..cf9b90299 100644
--- a/testsuite/example-deformer/CMakeLists.txt
+++ b/testsuite/example-deformer/CMakeLists.txt
@@ -2,7 +2,7 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # https://github.com/AcademySoftwareFoundation/OpenShadingLanguage
 
-cmake_minimum_required (VERSION 3.12)
+cmake_minimum_required (VERSION 3.15)
 project (osldeformer
          LANGUAGES CXX)
 
@@ -18,7 +18,7 @@ set (CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
 set (CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
 
 # Use C++11
-set (CMAKE_CXX_STANDARD 14 CACHE STRING "C++ standard to prefer (14, 17, 20, etc.)")
+set (CMAKE_CXX_STANDARD 17 CACHE STRING "C++ standard to prefer (17, 20, etc.)")
 set (CMAKE_CXX_STANDARD_REQUIRED ON)
 set (CMAKE_CXX_EXTENSIONS OFF)
 
diff --git a/testsuite/reparam-string/OPTIX b/testsuite/reparam-string/OPTIX
new file mode 100644
index 000000000..e69de29bb
diff --git a/testsuite/reparam-string/ref/out.txt b/testsuite/reparam-string/ref/out.txt
new file mode 100644
index 000000000..2a9d11a35
--- /dev/null
+++ b/testsuite/reparam-string/ref/out.txt
@@ -0,0 +1,4 @@
+Compiled test.osl -> test.oso
+test_string = initial value
+test_string = updated value
+
diff --git a/testsuite/reparam-string/run.py b/testsuite/reparam-string/run.py
new file mode 100755
index 000000000..1bbdbf76b
--- /dev/null
+++ b/testsuite/reparam-string/run.py
@@ -0,0 +1,15 @@
+#!/usr/bin/env python
+
+# Copyright Contributors to the Open Shading Language project.
+# SPDX-License-Identifier: BSD-3-Clause
+# https://github.com/AcademySoftwareFoundation/OpenShadingLanguage
+
+command += testshade(" ".join([
+    "--layer lay0",
+    "--param:type=string:interactive=1 test_string 'initial value'",
+    "test --iters 2",
+    "--reparam:type=string:interactive=1 lay0 test_string 'updated value'",
+]))
+
+outputs = [ "out.txt" ]
+
diff --git a/testsuite/reparam-string/test.osl b/testsuite/reparam-string/test.osl
new file mode 100644
index 000000000..0fb9be3d2
--- /dev/null
+++ b/testsuite/reparam-string/test.osl
@@ -0,0 +1,8 @@
+// Copyright Contributors to the Open Shading Language project.
+// SPDX-License-Identifier: BSD-3-Clause
+// https://github.com/AcademySoftwareFoundation/OpenShadingLanguage
+
+shader test(string test_string = "override me" [[ int interactive = 1 ]])
+{
+    printf("test_string = %s\n", test_string);
+}