A certain block game
Noob-proof (N)3DS Custom Firmware
N64 Game-Engine and Editor using libdragon & tiny3d
One framework for creating powerful cross-platform games
An unofficial PC port of the Xbox 360 version of Sonic Unleashed
Free game engine for development of desktop, mobile, and web games
A dead simple 2D game engine for Go
A tool for converting Xbox 360 shaders to HLSL
A promising chess program
Horse racing simulation
GameBoy clone
collection of ASCII puzzles that run in a commandline terminal.
An open-source Phantasy Star Online server for *nix
JASI - Java Event-Based Simulation Framework
Delphi Java - VRCalc++ OOSL (Script) and + (Binary Exec Distro)
Game engine to build text adventures.
Combat Flight Simulator for LINUX. WW2. Network and VOIP. Open-source.
PyCAPGE - Python Classic Adventure Point and Click Game Engine
TX Library is a tiny graphics library for Win32 written in C++.