After securing a license to the Quake engine (through the help of friend Michael Abrash of id Software) in late 1996, Newell and Harrington began working on Half-Life. Originally planned for release in late 1997, Half-Life launched on November 19, 1998. Valve acquired TF Software PTY Ltd, the makers of the Team Fortress mod for Quake, in May 1998 with the intent to create a standalone Team Fortress game. The Team Fortress Classic mod, essentially a port of the original Team Fortress mod for Quake, was released for Half-Life in 1999. Gearbox contributed much after the release of Half-Life. Gearbox Software is responsible for the Half-Life expansion packs, Half-Life: Opposing Force and Half-Life: Blue Shift, along with the home console versions of Half-Life for the Sega Dreamcast and Sony PlayStation 2 which included a third expansion pack called Half-Life: Decay, that enabled two-player split-screen co-op.
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