'''''Team Fortress 2''''' is a [[free-to-play]] team-based [[first-person shooter]] [[multiplayer video game|multiplayer]] video game developed by [[Valve Corporation]]. A sequel to the original [[mod (computer gaming)|mod]] ''[[Team Fortress]]'' based on the [[Source engine]], it was first released as part of the video game [[bundled software|compilation]] ''[[The Orange Box]]'' on October 10, 2007 for [[Microsoft Windows|Windows]] and the [[Xbox 360]].<ref name="release">{{cite web|url=http://biz.gamedaily.com/industry/news/?id=17582|title=Orange Box Goes Gold|publisher=GameDaily BIZ|accessdate=2007-10-22|date=September 26, 2007}}</ref> A [[PlayStation 3]] version then followed on November 22, 2007.<ref name="PS3 release">{{cite web| url=http://uk.gamespot.com/ps3/action/halflife2episode2/similar.html?mode=versions|title=The Orange Box|publisher=[[GameSpot]]|accessdate=2007-10-22}}</ref> The game was later released as a standalone package for Windows on April 9, 2008, and for Mac OS X two years later. ''Team Fortress 2'' is distributed online through the [[Steam (software)|Steam]] system, while retail distribution was handled by [[Electronic Arts]]. On June 23, 2011, the game became a [[free-to-play]] title, supported by [[microtransaction]]s for unique in-game equipment through Steam. The development of ''Team Fortress 2'' is led by John Cook and Robin Walker, the designers who originally created the ''[[Team Fortress]]'' [[mod (computer gaming)|modification]] for ''[[Quake (video game)|Quake]]'' in 1996.