A free version of half-life with co-op?

The developers of Sven Co-op, a nearly fifteen-years-old mod that lets you play Valve's original Half-Life cooperatively with friends online, announced that their creation is heading to Steam as a free stand-alone game. With huge improvements.

In a post published on the mod's official website, the team revealed that Valve not only agreed to put Sven Co-op on Steam as a separate game, but also gave them access to GoldSrc, the engine powering Half-Life and its expansions, Opposing Force and Blue Shift. This allows them to greatly improve user experience by making modifications and improvements directly to the game engine. Here's what all this exactly means, in the team's own words:

The next version of Sven Co-op will run as a standalone game using a custom build of the Half-Life engine.

The game will be FREE for all Steam users, including the official Half-Life campaign. A Half-Life purchase will not be required.

Automatic updates will be available using Steam's content delivery system dubbed SteamPipe. This will allow us to perform more frequent and rapid updates as needed.

Updates and new features will be added to the Half-Life engine, as well as a series of improvements to Half-Life's level editor called Hammer.

Increased Half-Life engine limits to allow for much larger and more detailed worlds.

Stability, performance, and gameplay improvements for everyone.
Currently there is no ETA for the stand-alone version of Sven Co-op, but the developers assured everyone that "more news and progress updates will be posted in the near future." Of course, if you can't wait and got a copy of Half-Life lying around, you can always try the mod as it is right now.

From kotaku