Valve has invited another 5,000 users to beta its digital distribution platform on the Linux operating system.
Newly invited beta testers will receive an email notification before the Thanksgiving weekend begins in the US.
The private external beta for Steam on Linux began in October this year, where a limited number of testers were selected from a pool of over 60,000 applicants.
The external beta started in October this year, and included Steam, one Valve game, and support for Ubuntu 12.04 and above. The initial round of invitations went out to 1,000 users.
Valve has a team of 11 people developing its Linux to makes games run on Ubuntu and has plans to accommodate other distributions of Linux. When the project began in 2011, Left 4 Dead 2 was the first game it began developing to work with a functioning Ubuntu build.
Steam is already available on PC, Mac, PlayStation 3, iOS and Android.