Softpedia reports
Steam is the world's largest digital game distribution platform, supporting all major operating systems, including Microsoft Windows, Mac OS X, and GNU/Linux or SteamOS, Valve's own distribution derived from the acclaimed Debian GNU/Linux OS.
[...] There are approximately 6,500 titles in the Steam library. Almost all of them are being supported on the Microsoft Windows platform, a little over 2,300 have support for the Mac OS X operating system, and 1,500 titles offer support for Valve's SteamOS and any other GNU/Linux distribution out there.
[...] Even more good news: [...] Many other games will have support for the Linux platform soon, mainly because Valve will finally release its Steam Machines gaming console / personal computer in November, which will be powered by the company's Debian-based SteamOS GNU/Linux operating system.
(Score: 2, Touché) by elixir on Tuesday September 22 2015, @06:13AM
Indeed, with a significant other. My wife chooses to run GNU/Linux as well.