Threewave is a
capture the flag modification for the hit FPS game
Quake III Arena. The latest version of it incorporates over ten new maps, and a brand new portal voting system.
In the portal (visited after every game if the server has it enabled) there are pictures of each map up on the wall. You simply choose what map you want to vote for, to play next, and run into the picture. Then you will go into one of 4 mini games, that all the players who have voted will enter.
After choosing a map you can then choose a gametype.
Original Capture the Flag
This recreates the CTF style used in Quake and Quake II, rather than their Quake III Arena brother.
Threewave Capture the Flag
This is almost identical to the CTF style that Q3 uses, but with different maps.
Capture Strike
Changing the game around a bit into a round based affair, Capture Strike sets you the task of playing as either the attackers or defenders. The objective being to grab the defenders flag or wipe out the opposition. Your main problem is that once your killed you don't respawn until the next round.
This is one of the best mods for Q3 in my opinion.