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.
Excalibur: Morgana's Revenge (EMR) is a first-person shooter game with an epic and in-depth story line. The player travels through time in the Jurassic period, Camelot period, and into the future to chase down Morgana. Using the Aleph One engine, EMR creates an amazing new world, making it an entirely fun and unique gaming experience.