While reading up on the history of the Halo trilogy, I found out about its predecessor, the Marathon trilogy; it’s one of the most awesome games ever! It’s like Halo except pixelated, as I describe it to my friends. It was released as open-source by bungie and is now super-enhanced from the original version by fans and can be played multiplayer over the internet (even co-op).
There are still quite a few people that play this game online, and it would be cool if more people got on multiplayer. I’m on there quite often as John Doe. If you love Halo, old games, and don’t have Xbox live, this is the next best thing. It’s available for Mac OS X, Windows, and Linux.