Valve has begun beta testing the Linux version of its digital distribution platform Steam.
The company has selected a limited number of testers from over 60,000 who applied in the first week after Valve opened registration.
More testers will be added as the beta continues.
The beta launches with 26 titles, including Valve's Team Fortress 2, and even includes the Steam Big Picture mode designed for use with a TV and controller.
The Steam client currently runs on Ubuntu 12.04, and Frank Crockett of the Steam for Linux team said Valve plans to add support for more distros in the future.
“This is a huge milestone in the development of PC gaming,” said Valve president and co-founder Gabe Newell.
“Steam users have been asking us to support gaming on Linux. We’re happy to bring rich forms of entertainment and our community of users to this open, customer-friendly platform.”
Valve announced plans for a Linux version of Steam as a "hedging strategy" to Windows 8, which Newell called "a disaster" for PC Gaming.