A VR version of Second Life was already in the works well before Oculus became a household name. I demoed the latest version recently and got a first-person, up-close look at a room full of carefully crafted items that I could inspect more closely than I would have been able to in the normal PC experience.
"One creator went into her virtual world in Oculus for the first time and was crying," Altberg said. "It's very powerful stuff."
Linden is not the only one trying to anticipate what a virtual world will look like in virtual reality. Linden's own founder, Philip Rosedale—who stepped down as CEO in 2010 and left the company's board last year—is working on an ambitious new made-for-VR world called High Fidelity.
Rosedale demoed an early prototype of High Fidelity at this year's Silicon Valley Virtual Reality Conference, calling it "a sensory experience" (seriously, we're not using the word game here).
Read MoreVirtual reality gaming set to become a real thing
"When I go into a crowded street, I expect there to be people," Rosedale said at SVVR. "And when I look at those people, I expect them to make eye contact with me."