In this repository you'll find the fully reversed source code for GTA III (master branch) and GTA VC (miami branch).

It has been tested and works on Windows, Linux, MacOS and FreeBSD, on x86, amd64, arm and arm64.
Rendering is handled either by original RenderWare (D3D8) or the reimplementation librw (D3D9, OpenGL 2.1 or above, OpenGL ES 2.0 or above).
Audio is done with MSS (using dlls from original GTA) or OpenAL.