The Verge: We just gave the Oculus Rift, a virtual reality headset, our Best of CES award. Guess who else is experimenting with virtual reality? Valve Software. At the 2013 Game Developers Conference in San Francisco, California, the same renowned video game publisher that's hard at work on the Steambox will also share its thoughts on VR, after spending a full year prototyping ways to create virtual reality hardware and software. Valve will host two 25-minute lectures entitled "Why Virtual Reality is Hard (And Where it Might be Going)" and "What We Learned Porting Team Fortress 2 to Virtual Reality" at the conference.