The ioquake3 community effort to continue supporting/developing id's
A very efficient tutor.
A console preference game for linux
A cross-platform port of Hexen II game.
Zoomable user interface (ZUI) with file manager, file viewers and more
Orx: Portable Game Engine
a multiplatform, full-featured GameBoy classic emulator
PAK file editor for Quake engine games
Multi-platform Nintendo Game Boy Color emulator written in Go
Fixes for X-Wing game binaries
A cross-platform 2D game engine
3D video music media player lyrics subtitles etc...
A cross-platform interpreter for many point-and-click adventure games
Text-based adventure game
Multi-platform game engine similar to old Megaman with a stage editor
A cross-platform, 3D interpreter to play LucasArts' Lua-based games
Open Game Bootstrap
Cross platform 2D/3D game engine written in C++11 & OpenGL ES 2/3
A generic 2D engine for any kind of game
Scriptable frontend for media applications.