Yes, There Are Portal 2 Linux References

[jcgeny]

SOURCE engine has been ported to OGL (SOURCE/STEAM is available for OSX plus there is still some plans to bring postalIII to linux which will use SOURCE) thus this isn't a renderer issue but more of a business/political issue as to whether SOURCE/sTEAM will come to linux

i learned that here , wiwi being the only one having directX , macos steam games are made with opengl renderer .
by the way to render the games , opengl or dx is the same . using macos files and disassemble them should help to gain time
for the rest a steam emu is needed and exists :

here is a link to the mostly used emulators :

http://forum.rev-crew.info/viewforum.php?f=3

here is a site that host a list of non-steam servers for most valve games :

http://css.setti.info/

of course some will say it s not legal , linux being a so little "market" that s why valve does not care about it .
the non-steam-linux seems the only way to interest gamers and so to have a legit steam for linux .

[KameZero]

Something else... like Steam for Linux perhaps? One can hope at least

Probably more like Desura I would guess.