High Fidelity, the stealth virtual reality startup from Second Life founder Philip Rosedale, just raised $2.5 million.

After debuting last April with $2.4 million in funding from True Ventures, Google Ventures, Kapor Capital, and Linden Lab, High Fidelity has raised a new, slightly larger round, according to an SEC filing today.

Interestingly enough, High Fidelity continues to operate in stealth mode; only vague statements on the company’s site reveal its purpose. The company began soliciting alpha-stage testers nearly two months ago on Twitter, but it has since kept relatively quiet.

Considering the site’s emphasis on cutting-edge virtual-reality experiments, High Fidelity feels more like an incubation company than a singular startup — like Kevin Rose’s Milk or the Twitter cofounder Biz Stone’s Obvious Corporation. Yet there’s no indication whether High Fidelity plans to release a single product or many. The company did not immediately respond to VentureBeat’s request for comment on the new round.

Facebook’s acquisition of Oculus Rift certainly pumps more excitement into the virtual reality space, although unlike Oculus Rift, it appears High Fidelity has no interest in gaming. High Fidelity hints that it will focus largely on re-creating social interactions in a virtual environment. Recent experiments by High Fidelity focus on physical interaction between two people [below].

Perhaps Mark Zuckerberg acquired the wrong virtual reality company?