OpenRA / OpenRA
Open Source real-time strategy game engine for early Westwood games such as Command & Conquer: Red Alert written in C# using SDL and OpenGL. Runs on Windows, Linux, *BSD and Mac OS X.
OpenRA / OpenRA
stride3d / stride
Stride (formerly Xenko), a free and open-source cross-platform C# game engine.
AssetRipper / AssetRipper
GUI application to analyze game files
SamboyCoding / Cpp2IL
Work-in-progress tool to reverse unity's IL2CPP toolchain.