Jailbreak: Source is a Source engine modification available for free to anyone that owns any game created by Valve Software. Jailbreak: Source is a first person shooter set in a rich variety of settings from Elizabethan England to Neo-Tokyo cities, inspired by the visual style of works such as “Timesplitters” and the addictive and frenetic action of “Unreal Tournament”. It combines the classic Jailbreak game type with non-stop arcade action to create a whole new gameplay experience.
http://www.jailbreaksource.com/
