Chocolate Doom is a Doom source port which aims to behave as closely as possible to the original DOS Doom executables ("Vanilla Doom"). It aims to be compatible with DOS Doom demos, configuration files, savegames, and bugs. As far as possible, it provides the same features that are available in the DOS version, along with the same "feel" of the original game.
GLoid is a 3D block game inspired by Arkanoid. It was originally written as an SDL and OpenGL exercise, but has developed into a full-featured, highly playable game with refined graphics and sound effects. It runs equally well on Windows, Linux, and Mac OS X, and has minimal hardware requirements.