What does HL2 mean in Computing?

Half Life 2

Half-Life 2 (stylized as HλLF-LIFE2), the sequel to Half-Life, is a first-person shooter video game and part of the Half-Life series. Developed by Valve Corporation, it was released on November 16, 2004, following a protracted five-year $40 million development, during which a substantial part of the project was leaked and distributed on the Internet. The game was developed alongside Valve's Steam software. It introduced the Source game engine and, because of Steam, was the first single-player video game to require online product activation. Like its predecessor, Half-Life 2 received critical acclaim. It was praised for its advanced physics, animation, sound, AI, graphics, and narrative. The game won 39 "Game of the Year" awards and the title of "Game Of The Decade" at the 2012 Spike Video Game Awards. Over 6.5 million copies of Half-Life 2 were sold at retail by December 3, 2008, (not including the number of sales via Steam). As of February 9, 2011, Half-Life 2 had sold over 12 million copies. Source: Wikipedia

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