Black Mesa is a Half-Life 2 total conversion remaking VALVe Software's award-winning PC game, Half-Life. Utilizing the Source engine, Black Mesa will reintroduce the player as Doctor Gordon Freeman, along with the original cast of memorable characters and environments seen in Half-Life. Black Mesa was founded to fully reconstruct the Half-Life universe utilizing Source to its fullest potential in terms of art detail, level sizes and code features. This total conversion will not require Half-Life: Source to play - only legitimate copies of Half-Life 2 and Counter-Strike: Source on Steam.
NOTE: Not to be confused with Half-Life: Source -- this is an enhanced remake built as a total conversion of Half-Life 2.