Half-Life is a series of first-person shooter games created and published by Valve. Since the release of the original Half-Life for Windows in 1998, several ports, expansion packs and sequels have been canceled, including projects developed by other studios.
In 1999, Valve canceled a Half-Life port for Mac developed by Logicware. Half-Life: Hostile Takeover, an expansion pack for Half-Life developed by 2015, Inc, was cancelled in 2000. In 2001, Sierra, the publisher of the original Half-Life, canceled a port for Dreamcast after Sega announced its discontinuation.
After releasing Half-Life 2: Episode Two in 2007, Valve struggled to settle on a direction for a new Half-Life game. Episode Three was canceled after Valve abandoned episodic development and began developing a new game engine, Source 2. Another Half-Life 2 episode, by Junction Point Studios, was canceled after Junction Point was acquired by Disney Interactive Studios. Valve moved the project to Arkane Studios, who developed it as Ravenholm, set in a town infested with zombies. Valve canceled it as they felt it was creatively restrained.
Valve developed Half-Life 3 between 2013 and 2014, experimenting with procedurally generated levels, but canceled it as the Source 2 engine was still unfinished. A virtual reality (VR) game set on a time-travelling ship, Borealis, was canceled as the VR technology and tools were not complete.