Envelop VR announced on Tuesday it has raised $4 million in series A funding as the virtual reality startup gets ready to launch its first product.

The round was led by Madrona Venture Group and announced on the same day VR enthusiasts are descending on the Meydenbauer Center in Bellevue, Wash. for the second annual SEA VR expo.

Envelop, which is led by video game industry veteran and Uber Entertainment CEO Bob Berry, is essentially creating an operating system for VR with the hope of one day creating a more immersive computing experience. Instead of staring at a screen all day, Envelop sees a day where users will work with a headset on inside a virtual environment.

A select group of virtual reality developers will get their hands on Envelop’s technology later this winter and will have a chance start writing code and creating content without the typical constraints they face when using a typical desktop work environment.

This is Envelop’s second round of funding this year, as the Bellevue-based company raised $2 million from a group of high-power angels in June. Raising this kind of financing is a challenging feat, as the VR industry still hasn’t seen mainstream adoption. VR entrepreneurs tend to find themselves spending just as much time explaining the technology and convincing investors the market is real as they do actually selling their business.

But Madrona said when it raised its most recent $300 million fund in June that VR was one area of particular interest.

“We think the next decade plus is going to be a big transformation, and there are going to be a lot of winners up and down that stack,” Madrona’s Matt McIlwain told GeekWire back then. “We think the combination of what Valve is doing here in town, the strong presence of Oculus and the Facebook team here, and what Microsoft is doing with HoloLens and other initiatives and undoubtedly others in town are working on stuff as well, that this is a great area for VR and AR investments.”

Now, the Seattle venture firm is putting its money where its mouth is, backing its first VR startup.

“Matt [McIlwain] and the Madrona team share our same incredible passion about this transformative technology and its vast potential,” Berry said in Wednesday press release. “These immersive technologies offer an entirely new way to interact with computers, data and humans. We expect to see the same explosive growth as we did with the mobile phone industry.”