Shockingly Valve didn't announce Half Life 3 yesterday, but they did have plenty to say at the Games Development Conference (GDC) – including the announcement of Source Engine 2.

Further still, Source 2 will be free for all to use in response to how "important user generated content is becoming," according to Valve's Jay Stelly.

"With Source 2, our focus is increasing creator productivity," he said. "Source 2 is designed not just for the professional developer, but enabling gamers themselves to participate in the creation and development of their favourite games."

Source 2 is the follow up to the original Source engine, which released in the summer of 2004 and which has been the basis of every Valve classic since – Half Life 2, Left 4 Dead, Portal, and third party indies such as Garry's Mod and The Stanley Parable.

The versatile and enduring engine was also used to create Xbox One and PC multiplayer shooter Titanfall last year.

Recently Epic offered its Unreal Engine 4 for free, as did Unity Technologies with its Unity 5 engine.

Valve of course offered no information on whether any games of its creation are being built in the engine, and also offered no time frame for its release.

Could one of the games Valve are sure to be working on be Half Life 3? The answer can probably be found at the bottom of this beer bottle.