OpenArena Windows, Mac, Linux, Linux64 game

It is an open source multiplayer first-person shooter. It uses the id Tech 3 engine source code (which is released under the GNU General Public License v2), and fills in the blank with all new media to make a playable game.

• It's not a 'scavenge the internet for stuff' compilation project, the only things scavenged are some maps, which are OKAY because their source was released under the GPL.
• Everything is strictly open source so they can be improved forever (and ever). 
• The additional "Missionpack" game types and weapons are merged into the base, so you get to lay the mines in overload maps. 
• There's more game types than the base game, like Domination, Last Man Standing, and what not. ("What not" does not refer to a gametype of that name - Ed)
• Uses ioq3 for various feature additions, but it is not ioq3 dependent; it's also intended to be vanilla compatible. (The only thing that won't work is ogg music) 
• The art direction is different and not strictly 'gothic'. There's more of a eastern slant than the usual 'put skulls n' blood all over it's cool' you find in most games. 
• It's not next-gen, and computer compatibility range is wide enough to run on that dusty Pentium II in your attic. 
• There are bots, perfect for when you're stranded on an island. 
• There's also people playing it on the internet.
• It is Free Software, so there's no guilt in downloading it and redistributing it.

OpenArena is licensed under the GNU GPL version 2 - data and engine. Anyone can contribute to it, if it complies with the GNU GPL.

WARNING: OpenArena contains Mature Content. I'm serious. If you don't like shooting the bloody guts and beating hearts out of voluptuous barely modest combatants then don't play it, or play without the mature pk3 file and use com_blood 0/cg_showGibs 0 (but be aware that pure servers may not agree with this).