Five Hundred is a card game for four players similar to Euchre or Bridge, especially popular in Australia and New Zealand. The wikipedia page has a comprehensive description of gameplay. This version is implemented in C++/Qt. It incorporates graphics from the svg-cards project. Computer players are scriptable in Lua.
FCEUX is a Nintendo Entertainment System (NES), Famicom, and Famicom Disk System (FDS) emulator. It supports both PAL (European) and NTSC (USA/JPN) modes. It supports both Windows and SDL versions for cross compatibility. The FCEUX concept is that of an "all in one" emulator that offers accurate emulation and the best options for both casual play and a variety of more advanced emulator functions. For advanced users, FCEUX offers tools for debugging, ROM-hacking, map making, tool-assisted movies, and Lua scripting. FCEUX is an evolution of the FCE Ultra emulator. FCEUX merges elements from FCEU Ultra, FCEU rerecording, FCEUXD, FCEUXDSP, FCEUXDSP CE, and FCEU-mm into a single branch of FCEU.
EGSL is a small interpreter which can execute Lua scripts. It includes some functions for fast and easy game development. These are image manipulation functions, functions for 2D drawing, sound and music, input via mouse, keyboard, and joypad, and some helper functions. The engine is based on SDL, SDL_gfx, and SDL_mixer, and additionally on SDL_image on Haiku-OS.
Naev is a 2D space trading and combat game, in a similar vein as Escape Velocity. Naev is played from a top-down perspective, featuring fast-paced combat, many ships, a large variety of equipment, and a large galaxy to explore. The game is highly open-ended, letting you proceed at your own pace.