diff --git a/src/input_output/FGLog.cpp b/src/input_output/FGLog.cpp
index 35b7ff9d6..f1c00cc4c 100644
--- a/src/input_output/FGLog.cpp
+++ b/src/input_output/FGLog.cpp
@@ -1,9 +1,9 @@
 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
- Module:       FGOutputType.cpp
+ Module:       FGLog.cpp
  Author:       Bertrand Coconnier
  Date started: 05/03/24
- Purpose:      Manage output of sim parameters to file or stdout
+ Purpose:      Manage the logging of messages
 
   ------------- Copyright (C) 2024 Bertrand Coconnier -------------
 
@@ -26,8 +26,8 @@
 
 FUNCTIONAL DESCRIPTION
 --------------------------------------------------------------------------------
-This is the place where you create output routines to dump data for perusal
-later.
+This is the place where the logging of messages is managed. The messages can be
+sent to the console, to a file, etc.
 
 HISTORY
 --------------------------------------------------------------------------------
diff --git a/src/input_output/FGLog.h b/src/input_output/FGLog.h
index 05e068a7b..efee734f9 100644
--- a/src/input_output/FGLog.h
+++ b/src/input_output/FGLog.h
@@ -97,7 +97,7 @@ class JSBSIM_API FGLogger
 {
 public:
   virtual ~FGLogger() {}
-  virtual void SetLevel(LogLevel level) { level = level; }
+  virtual void SetLevel(LogLevel l) { level = l; }
   virtual void FileLocation(const std::string& filename, int line) {}
   void SetMinLevel(LogLevel level) { min_level = level; }
   virtual void Message(const std::string& message) = 0;
@@ -148,7 +148,7 @@ class JSBSIM_API FGLogConsole : public FGLogger
 {
 public:
   void FileLocation(const std::string& filename, int line) override
-  { buffer << std::endl << "In file " << filename << ": line" << line << std::endl; }
+  { buffer << std::endl << "In file " << filename << ": line " << line << std::endl; }
   void Format(LogFormat format) override;
   void Flush(void) override;
 
diff --git a/tests/unit_tests/CMakeLists.txt b/tests/unit_tests/CMakeLists.txt
index 8a737be5f..bd5a8c4b7 100644
--- a/tests/unit_tests/CMakeLists.txt
+++ b/tests/unit_tests/CMakeLists.txt
@@ -19,7 +19,8 @@ set(UNIT_TESTS FGColumnVector3Test
                FGPropertyManagerTest
                FGAtmosphereTest
                FGAuxiliaryTest
-               FGMSISTest)
+               FGMSISTest
+               FGLogTest)
 
 
 foreach(test ${UNIT_TESTS})
diff --git a/tests/unit_tests/FGLogTest.h b/tests/unit_tests/FGLogTest.h
new file mode 100644
index 000000000..1c82e44f7
--- /dev/null
+++ b/tests/unit_tests/FGLogTest.h
@@ -0,0 +1,422 @@
+#include <cxxtest/TestSuite.h>
+#include <input_output/FGLog.h>
+#include <input_output/FGXMLElement.h>
+
+class DummyLogger : public JSBSim::FGLogger
+{
+public:
+  JSBSim::LogLevel GetLogLevel() const { return level; }
+  void Message(const std::string& message) override { buffer.append(message); }
+  void FileLocation(const std::string& filename, int line) override {
+    buffer.append(filename);
+    buffer.append(":");
+    buffer.append(std::to_string(line));
+  }
+  void Format(JSBSim::LogFormat format) override {
+  switch (format)
+  {
+  case JSBSim::LogFormat::NORMAL:
+    buffer.append("NORMAL");
+    break;
+  default:
+    buffer.append("UNKNOWN");
+    break;
+  }
+  }
+  void Flush(void) override { flushed = true; }
+
+  std::string buffer;
+  bool flushed = false;
+};
+
+class FGLogTest : public CxxTest::TestSuite
+{
+public:
+void testConstructor() {
+  auto logger = std::make_shared<DummyLogger>();
+  TS_ASSERT(!logger->flushed);
+  TS_ASSERT(logger->buffer.empty());
+  TS_ASSERT_EQUALS(logger->GetLogLevel(), JSBSim::LogLevel::BULK);
+
+  JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+  TS_ASSERT(log.str().empty());
+  TS_ASSERT(!logger->flushed);
+  TS_ASSERT(logger->buffer.empty());
+  TS_ASSERT_EQUALS(logger->GetLogLevel(), JSBSim::LogLevel::INFO);
+}
+
+void testDestructor() {
+  auto logger = std::make_shared<DummyLogger>();
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    TS_ASSERT(log.str().empty());
+    TS_ASSERT(!logger->flushed);
+  }
+  TS_ASSERT(logger->buffer.empty());
+  TS_ASSERT(logger->flushed);
+}
+
+void testCharMessage() {
+  auto logger = std::make_shared<DummyLogger>();
+  const char* message = "Hello, World!";
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    log <<message;
+    TS_ASSERT_EQUALS(log.str(), message);
+    TS_ASSERT(!logger->flushed);
+    TS_ASSERT(logger->buffer.empty());
+  }
+  TS_ASSERT(logger->flushed);
+  TS_ASSERT_EQUALS(logger->buffer, message);
+}
+
+void testStringMessage() {
+  auto logger = std::make_shared<DummyLogger>();
+  std::string message = "Hello, World!";
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    log << message;
+    TS_ASSERT_EQUALS(log.str(), message);
+    TS_ASSERT(!logger->flushed);
+    TS_ASSERT(logger->buffer.empty());
+  }
+  TS_ASSERT(logger->flushed);
+  TS_ASSERT_EQUALS(logger->buffer, message);
+}
+
+void testConcatenatedMessages() {
+  auto logger = std::make_shared<DummyLogger>();
+  std::string message1 = "Hello";
+  std::string message2 = "World!";
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    log << message1 << " " << message2;
+    TS_ASSERT_EQUALS(log.str(), message1 + " " + message2);
+    TS_ASSERT(!logger->flushed);
+    TS_ASSERT(logger->buffer.empty());
+  }
+  TS_ASSERT(logger->flushed);
+  TS_ASSERT_EQUALS(logger->buffer, message1 + " " + message2);
+}
+
+void testEndl() {
+  auto logger = std::make_shared<DummyLogger>();
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    log << "Hello" << std::endl << "World!";
+    TS_ASSERT_EQUALS(log.str(), "Hello\nWorld!");
+    TS_ASSERT(!logger->flushed);
+    TS_ASSERT(logger->buffer.empty());
+  }
+  TS_ASSERT(logger->flushed);
+  TS_ASSERT_EQUALS(logger->buffer, "Hello\nWorld!");
+}
+
+void testNumbers() {
+  auto logger = std::make_shared<DummyLogger>();
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    log << 1 << 2.1 << -3.4f;
+    TS_ASSERT_EQUALS(log.str(), "12.1-3.4");
+    TS_ASSERT(!logger->flushed);
+    TS_ASSERT(logger->buffer.empty());
+  }
+  TS_ASSERT(logger->flushed);
+  TS_ASSERT_EQUALS(logger->buffer, "12.1-3.4");
+}
+
+void testSetPrecision() {
+  auto logger = std::make_shared<DummyLogger>();
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    log << std::setprecision(3) << 1.23456789;
+    TS_ASSERT_EQUALS(log.str(), "1.23");
+    TS_ASSERT(!logger->flushed);
+    TS_ASSERT(logger->buffer.empty());
+  }
+  TS_ASSERT(logger->flushed);
+  TS_ASSERT_EQUALS(logger->buffer, "1.23");
+}
+
+void testSetWidthRight() {
+  auto logger = std::make_shared<DummyLogger>();
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    log << std::setw(5) << 123;
+    TS_ASSERT_EQUALS(log.str(), "  123");
+    TS_ASSERT(!logger->flushed);
+    TS_ASSERT(logger->buffer.empty());
+  }
+  TS_ASSERT(logger->flushed);
+  TS_ASSERT_EQUALS(logger->buffer, "  123");
+}
+
+void testSetWidthLeft() {
+  auto logger = std::make_shared<DummyLogger>();
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    log << std::left << std::setw(5) << 123;
+    TS_ASSERT_EQUALS(log.str(), "123  ");
+    TS_ASSERT(!logger->flushed);
+    TS_ASSERT(logger->buffer.empty());
+  }
+  TS_ASSERT(logger->flushed);
+  TS_ASSERT_EQUALS(logger->buffer, "123  ");
+}
+
+void testPath() {
+  auto logger = std::make_shared<DummyLogger>();
+  SGPath path("path/to");
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    log << (path/"file");
+    TS_ASSERT_EQUALS(log.str(), "Path \"path/to/file\"");
+    TS_ASSERT(!logger->flushed);
+    TS_ASSERT(logger->buffer.empty());
+  }
+  TS_ASSERT(logger->flushed);
+  TS_ASSERT_EQUALS(logger->buffer, "Path \"path/to/file\"");
+}
+
+void testColumnVector3() {
+  auto logger = std::make_shared<DummyLogger>();
+  JSBSim::FGColumnVector3 vec(1, 2, 3);
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    log << vec;
+    TS_ASSERT_EQUALS(log.str(), "1 , 2 , 3");
+    TS_ASSERT(!logger->flushed);
+    TS_ASSERT(logger->buffer.empty());
+  }
+  TS_ASSERT(logger->flushed);
+  TS_ASSERT_EQUALS(logger->buffer, "1 , 2 , 3");
+}
+
+void testFormatOnly() {
+  auto logger = std::make_shared<DummyLogger>();
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    TS_ASSERT(!logger->flushed);
+    TS_ASSERT(logger->buffer.empty());
+    log << JSBSim::LogFormat::NORMAL;
+    TS_ASSERT(log.str().empty());
+    TS_ASSERT(!logger->flushed);
+    TS_ASSERT_EQUALS(logger->buffer, "NORMAL");
+  }
+  TS_ASSERT(logger->flushed);
+  TS_ASSERT_EQUALS(logger->buffer, "NORMAL");
+}
+
+void testClosingFormat() {
+  auto logger = std::make_shared<DummyLogger>();
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    log << "Hello,";
+    TS_ASSERT_EQUALS(log.str(), "Hello,");
+    TS_ASSERT(!logger->flushed);
+    TS_ASSERT(logger->buffer.empty());
+    log << JSBSim::LogFormat::NORMAL;
+    TS_ASSERT(log.str().empty());
+    TS_ASSERT(!logger->flushed);
+    TS_ASSERT_EQUALS(logger->buffer, "Hello,NORMAL");
+  }
+  TS_ASSERT(logger->flushed);
+  TS_ASSERT_EQUALS(logger->buffer, "Hello,NORMAL");
+}
+
+void testMidFormat() {
+  auto logger = std::make_shared<DummyLogger>();
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    log << "Hello,";
+    TS_ASSERT_EQUALS(log.str(), "Hello,");
+    TS_ASSERT(!logger->flushed);
+    TS_ASSERT(logger->buffer.empty());
+    log << JSBSim::LogFormat::NORMAL;
+    TS_ASSERT(log.str().empty());
+    TS_ASSERT(!logger->flushed);
+    TS_ASSERT_EQUALS(logger->buffer, "Hello,NORMAL");
+    log << " World!";
+    TS_ASSERT_EQUALS(log.str(), " World!");
+    TS_ASSERT(!logger->flushed);
+    TS_ASSERT_EQUALS(logger->buffer, "Hello,NORMAL");
+  }
+  TS_ASSERT(logger->flushed);
+  TS_ASSERT_EQUALS(logger->buffer, "Hello,NORMAL World!");
+}
+
+void testXMLLogging() {
+  auto logger = std::make_shared<DummyLogger>();
+  JSBSim::Element el("element");
+  el.SetFileName("file.xml");
+  el.SetLineNumber(42);
+  {
+    JSBSim::FGXMLLogging log(logger, &el, JSBSim::LogLevel::DEBUG);
+    TS_ASSERT(log.str().empty());
+    TS_ASSERT_EQUALS(logger->buffer, "file.xml:42");
+    TS_ASSERT(!logger->flushed);
+    TS_ASSERT_EQUALS(logger->GetLogLevel(), JSBSim::LogLevel::DEBUG);
+  }
+  TS_ASSERT(logger->flushed);
+  TS_ASSERT_EQUALS(logger->buffer, "file.xml:42");
+}
+};
+
+class FGLogConsoleTest : public CxxTest::TestSuite
+{
+public:
+void testNormalMessage() {
+  auto logger = std::make_shared<JSBSim::FGLogConsole>();
+  std::ostringstream buffer;
+  auto cout_buffer = std::cout.rdbuf();
+  std::cout.rdbuf(buffer.rdbuf());
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::DEBUG);
+    log << "Hello, World!";
+  }
+  std::cout.rdbuf(cout_buffer);
+  TS_ASSERT_EQUALS(buffer.str(), "Hello, World!");
+}
+
+void testErrorMessage() {
+  auto logger = std::make_shared<JSBSim::FGLogConsole>();
+  std::ostringstream buffer;
+  auto cerr_buffer = std::cerr.rdbuf();
+  std::cerr.rdbuf(buffer.rdbuf());
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::ERROR);
+    log << "Hello, World!";
+  }
+  std::cerr.rdbuf(cerr_buffer);
+  TS_ASSERT_EQUALS(buffer.str(), "Hello, World!");
+}
+
+void testXMLLogging() {
+  auto logger = std::make_shared<JSBSim::FGLogConsole>();
+  std::ostringstream buffer;
+  auto cout_buffer = std::cout.rdbuf();
+  std::cout.rdbuf(buffer.rdbuf());
+  JSBSim::Element el("element");
+  el.SetFileName("name.xml");
+  el.SetLineNumber(42);
+  {
+    JSBSim::FGXMLLogging log(logger, &el, JSBSim::LogLevel::DEBUG);
+  }
+  std::cout.rdbuf(cout_buffer);
+  TS_ASSERT_EQUALS(buffer.str(), "\nIn file name.xml: line 42\n");
+}
+
+void testRedFormat() {
+  auto logger = std::make_shared<JSBSim::FGLogConsole>();
+  std::ostringstream buffer;
+  auto cout_buffer = std::cout.rdbuf();
+  std::cout.rdbuf(buffer.rdbuf());
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    log << JSBSim::LogFormat::RED;
+    log << "Hello, World!";
+    log << JSBSim::LogFormat::RESET;
+  }
+  std::cout.rdbuf(cout_buffer);
+#ifdef _MSC_VER
+  TS_ASSERT_EQUALS(buffer.str(), "Hello, World!");
+#else
+  TS_ASSERT_EQUALS(buffer.str(), "\033[31mHello, World!\033[0m");
+#endif
+}
+
+void testCyanFormat() {
+  auto logger = std::make_shared<JSBSim::FGLogConsole>();
+  std::ostringstream buffer;
+  auto cout_buffer = std::cout.rdbuf();
+  std::cout.rdbuf(buffer.rdbuf());
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    log << JSBSim::LogFormat::BLUE;
+    log << "Hello, World!";
+    log << JSBSim::LogFormat::RESET;
+  }
+  std::cout.rdbuf(cout_buffer);
+#ifdef _MSC_VER
+  TS_ASSERT_EQUALS(buffer.str(), "Hello, World!");
+#else
+  TS_ASSERT_EQUALS(buffer.str(), "\033[34mHello, World!\033[0m");
+#endif
+}
+
+void testBoldFormat() {
+  auto logger = std::make_shared<JSBSim::FGLogConsole>();
+  std::ostringstream buffer;
+  auto cout_buffer = std::cout.rdbuf();
+  std::cout.rdbuf(buffer.rdbuf());
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    log << JSBSim::LogFormat::BOLD;
+    log << "Hello, World!";
+    log << JSBSim::LogFormat::RESET;
+  }
+  std::cout.rdbuf(cout_buffer);
+#ifdef _MSC_VER
+  TS_ASSERT_EQUALS(buffer.str(), "Hello, World!");
+#else
+  TS_ASSERT_EQUALS(buffer.str(), "\033[1mHello, World!\033[0m");
+#endif
+}
+
+void testNormalFormat() {
+  auto logger = std::make_shared<JSBSim::FGLogConsole>();
+  std::ostringstream buffer;
+  auto cout_buffer = std::cout.rdbuf();
+  std::cout.rdbuf(buffer.rdbuf());
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    log << JSBSim::LogFormat::NORMAL;
+    log << "Hello, World!";
+    log << JSBSim::LogFormat::RESET;
+  }
+  std::cout.rdbuf(cout_buffer);
+#ifdef _MSC_VER
+  TS_ASSERT_EQUALS(buffer.str(), "Hello, World!");
+#else
+  TS_ASSERT_EQUALS(buffer.str(), "\033[22mHello, World!\033[0m");
+#endif
+}
+
+void testUnderlineFormat() {
+  auto logger = std::make_shared<JSBSim::FGLogConsole>();
+  std::ostringstream buffer;
+  auto cout_buffer = std::cout.rdbuf();
+  std::cout.rdbuf(buffer.rdbuf());
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    log << JSBSim::LogFormat::UNDERLINE_ON;
+    log << "Hello, World!";
+    log << JSBSim::LogFormat::UNDERLINE_OFF;
+  }
+  std::cout.rdbuf(cout_buffer);
+#ifdef _MSC_VER
+  TS_ASSERT_EQUALS(buffer.str(), "Hello, World!");
+#else
+  TS_ASSERT_EQUALS(buffer.str(), "\033[4mHello, World!\033[24m");
+#endif
+}
+
+void testDefaultFormat() {
+  auto logger = std::make_shared<JSBSim::FGLogConsole>();
+  std::ostringstream buffer;
+  auto cout_buffer = std::cout.rdbuf();
+  std::cout.rdbuf(buffer.rdbuf());
+  {
+    JSBSim::FGLogging log(logger, JSBSim::LogLevel::INFO);
+    log << JSBSim::LogFormat::DEFAULT;
+    log << "Hello, World!";
+    log << JSBSim::LogFormat::RESET;
+  }
+  std::cout.rdbuf(cout_buffer);
+#ifdef _MSC_VER
+  TS_ASSERT_EQUALS(buffer.str(), "Hello, World!");
+#else
+  TS_ASSERT_EQUALS(buffer.str(), "\033[39mHello, World!\033[0m");
+#endif
+}
+};