Black Mesa (formerly Black Mesa: Source) is a Half-Life 2 remaking of Valve’s award-winning PC game, Half-Life. Utilizing the Source engine, Black Mesa re-introduces Doctor Gordon Freeman, along with the original characters and environments of Half-Life.
Black Mesa was built and founded on the basis that Half-Life: Source didn’t fully live up to the potential of a Source engine port of Half-Life. The project is being built from scratch and is not a port of Half Life maps and models into the Source Engine. The storyline used in Half Life is being re-created with a new polished Source Engine version with new models, maps, soundtrack, voice acting and textures.
Black Mesa will be free, obviously, to download and only requires a Source Engine game installed on Steam. For more details check out their website . Black Mesa is said to be available on September 14th, but the project has been pushed back numerous times so we shall see.
Check out the side by side comparison of the original Half life and the Black Mesa textures below: