When Half-Life 2 first came out, the game’s biggest online draw wasn’t its deathmatch multiplayer, but an unusual multiplayer physics mod known as Garry’s Mod. Designed to allow players to build their own environments, it was a major hit, selling out millions of copies when it eventually became widely available on Steam.

For Portal players, it looks like that same sense of creation has convinced Valve to produce some awesome new content. The Portal 2 Puzzle Creator, a Creation Kit of sorts for the Portal engine, is coming out relatively soon on Steam. The Puzzle Creator uses a simple drag-and-drop interface to allow gamers to create their own Portal levels without having to understand complex 3D design.

The Puzzle Creator is currently in internal beta testing, and given Valve’s previous record of putting games out on time, we’re not expecting it to hit steam in the next few weeks. However, at some time in the next few months, gamers will be able to create their own Portal puzzles with relative ease – a feature that’s bound to increase interest in the award-winning game.

We’ll keep you posted as development continues on the Puzzle Creator and it eventually hits Steam shelves – if there is such a thing – around the world. For now, there are plenty of third-party mods to keep the Portal spirit alive, as well as the two awesome games developed in-house by Valve.