You don't have to wait for Steam to publish Greenlight winner Black Mesa Source, the Half Life 2-based recreation of Half Life. The team has released the Half Life 2 total conversion for free through its own website.

You can also download the file directly from Joystiq.

So if the game's out and free, why does it need to be on Steam? The developers explain on the Greenlight page: "When we are on Steam we'll be able to reach more players and make installation and future updates easy for everyone!" Making updates more convenient is always a noble goal.