The latest Humble Bundle offers a total of six (if you pay more than the average price - four if you decide not to) Warner Bros. Games. All of these games run on Steam for Windows, though one game - Batman: Arkham City - is also available for Mac.
There are several caveats to this bundle including the fact that all the games require a Steam account, only one game is available for Mac, and none of them are available for Linux users... The four initial titles are Batman: Arkham Asylum GOTY, F.E.A.R. 2: Project Origin, F.E.A.R. 3, and Lord of the Rings: War in the North. Paying more than the average price (currently $4.38) you'll get Scribblenauts Unlimited and Batman: Arkham City GOTY.
The charity this time around is We Can Be Heroes, which raises awareness and the funds needed to fight the hunger crisis in the Horn of Africa and to bring aid to eight million people who are in urgent need of assistance. The campaign is lead by DC Entertainment’s popular comic book heroes Superman, Batman, Wonder Woman, Green Lantern, The Flash, Aquaman and Cyborg. Since launching the campaign in early 2012, the charity has helped more than five million people in the Horn of Africa.
For more information on the Humble Warner Bros. Games Bundle, check out www.humblebundle.com.