Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
Linux platform has made its first appearance on Steam website. Few days back, Valve added a zombie Tux to Left4Dead 2 website announcing that it will head to Linux soon and now a Linux platform filter has been added to Steam Greenlight.
Steam Greenlight is a new initiative by Valve where community votes for games submitted by developers. If Valve finds that a game has generated lots of interest, then it gets included in Steam game library.
A Linux filter can mean couple of things.