Black Mesa Source is a highly ambitious project that has been in development for eight years, and finally released on September 14th, 2012.
The first 14 chapters are available immediately, with the final five including the ending to be released alongside Black Mesa: Deathmatch once it is ready.
The mod began when two separate teams discovered they were working towards the same goal: updating Half-Life 1 to the Source engine. They combined to form the original 13 members, and over the course of the next eight years redid the entire game, top to bottom.
The graphical revamp is excellent, and the original air of Half Life 1 is complimented well by the updated Source engine. Apart from your crowbar being encountered at a slightly later stage, and some other minor tweaks, the course of the story and the level design is largely untouched, right down to the iconic elevator full of scientists plummeting to their death.
The voice acting is excellent, very consistent, and although you can definitely tell it’s not the original Doctor Kleiner, the Black Mesa version has perfectly captured his awkward lilt.
Black Mesa Source is incredibly well polished, and I think that Valve could easily have developed it and sold it for actual money, had they not been so busy squatting on Episode 3. It’s absolutely free, so there is no reason for you not to check it out. All that it requires is that you have one or more games that use the Source engine.