Valve Software's experiments with virtual reality, most recently exposed as a "VR Mode" of its popular free-to-play shooter Team Fortress 2, are actually just an offshoot of the company's longer-term goal: augmented reality. The dozens of AR markers plastered to the three walls of Valve programmer Joe Ludwig's shared office are testament to that (seen above). "We're mostly looking at a software level. We've talked to a bunch of different display vendors on the augmented reality side, and none of them are quite ready to go yet," L
