War is a plugin for Bukkit that adds PVP arenas and team deathmatch gamemodes to Minecraft servers.
Visit http://war.tommytony.com for more info, videos and links.
You can find the newest release at https://github.com/Jakllp/war/releases/tag/latest.
All releases, including pre-releases are available at https://github.com/Jakllp/war/releases/.
tommytony started the plugin in December 2010 on hMod and has been maintaining it since with the help of contributors. Reach him at taoneill@tommytony.com.
War is licensed loosely under the MIT License (but still comes with the weird baggage of Bukkit licensing)