Black Mesa: Source

http://blackmesasource.com/

Yes.

For those who don’t know what Black Mesa: Source is, it is a complete re-make of Half-Life 1 in the Source Engine. It isn’t a port of the game, it is completely re-made from scratch. And it shall be awesome. And free.
So, as I said

Yes.

Yeah, they’ve improved the graphics, and redone the dialogue also with new voice actors. I think that’s it really, but should still be good. I hope there is a way to put it into the synergy mod on steam for multiplayer xd