RetroArch is a frontend for emulators, game engines and media players.
A cross-platform PSP emulator
The game engine for everyone
Mangos ZERO is a server for World of Warcraft
The Playstation 2 emulator
CTFs as you need them
C# application with primary purpose of farming Steam cards
Set of Python modules designed for writing video games
Compatibility tool for Steam Play based on Wine and other components
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
New Godot bindings for Swift
Open source Old School RuneScape client
Mod manager for the video game RimWorld
The ioquake3 community effort to continue supporting/developing id's
ThinkPHP Framework
Open source library for creative expression on the web, desktop, etc.
Homebrew development library for Nintendo 3DS/Horizon OS user mode
dhewm 3 main repository
Stride (formerly Xenko), a free and open-source cross-platform C# game
3D Engine c++
An Ubuntu remix for both new and experienced Linux sophisticates
A cross-platform port of Hexen II game.
kernel mode mouse accel