https://www.cnet.com/news/steamvr-for-windows-mixed-reality-leaves-early-access/

In a market where "Early Access" can last for years, SteamVR for Windows Mixed Reality spent a remarkably short time there; only about five months. This week, in conjunction with Microsoft's announcement of its Windows 10 April 2018 Update, Steam announced that the program was ready for prime time.

For those unfamiliar with it, Early Access is the equivalent of a beta for games. They differ from betas because you frequently have to pay for the privilege.