We've been expecting big things from Valve at GDC 2015, and it's just delivered the motherload.

First, fulfilling its promise from months ago, it announced its plans for the long-overdue Steam Machines. They'll be launching in the fall, but Valve is releasing a device called Steam Link, a $50 (about £32, $64) streaming box that will let you broadcast games from the PC to the TV. That will support 1080p at 60Hz with low latency.

Valve also confirmed the final specs of its Steam Controller, which we'll be wrapping our hands around this week. The Controller will have both touch (haptic pads still in place, then) and motion capabilities.

Third was VR, with Valve revealing a piece of software called Lighthouse ahead of the launch of its HTC Vive headset. This will let VR headsets calculate their surrounding environment for the all-important positional tracking.

"We continue to see very strong growth in PC Gaming, with Steam growing 50% in the last 12 months," said Valve president Gabe Newell. "With these announcements we hope that we are helping build on that momentum."

One more thing

But there was one final surprise from Gabe Newell and co - Source 2. Valve announced the next generation of its game engine, which will be available for free to content developers.

This is a pretty big deal, as the original Source was launched over 10 years ago. The first Source debuted with the launch of Counter-Strike: Source, so we can probably expect some sort of game announcement from Valve very soon.

Nobody say it.