There are many different ways to use Wasm modules, and many different conventions, language-specific ABIs, and toolchain-specific ABIs. This document describes ABI features intended to be common across all ABIs.
If a module exports a function named _initialize with no arguments and no
return values, and does not export a function named _start, the toolchain
that produced my assume that on any instance of the module, this _initialize
function is called before any other exports are accessed.
This is intended to support language features such as C++ static constructors, as well as "top-level scripts" in many scripting languages, which can't use the [wasm start function] because they may call imports that need to access the module's exports. In use cases that don't need this, the wasm start function should be used.