Steam is now officially available on Linux.

Support for the open-source operating system was added today, and it joins Windows and Mac OS on the distribution platform.

To celebrate, Valve has discounted all 54 Linux-compatible games, as well as their Mac and Windows equivalents.

Games on sale include Trine 2 for US$3.74, Bastion for US$3.74, and FTL for US$4.99.

Valve suggests those looking to switch to Linux try Ubuntu, which is managed by Canonical.

From there, full Steam installation instructions are on the Ubuntu wiki.

Note that Steam for Linux is only supported on Ubuntu 12.04 LTS or 12.10 with the Unity, Gnome, or KDE desktop.

Ubuntu support was added to Steam due to growing demand from gamers and developers, said Canonical director of consumer applications David Pitkin.

“We expect a growing number of game developers to include Ubuntu among their target platforms.

“We’re looking forward to seeing triple-A games developed with Ubuntu in mind as part of a multiplatform day and date release on Steam.”

Last year Valve CEO Gabe Newell called Windows 8 “a catastrophe for everybody in the PC space”.

The upcoming Steam Box will run on Linux.