The titles for this third bundle include Trine, Shadowgrounds, Shadowgrounds: Survivor, Jack Claw, and Splot. The Shadowgrounds series plus Trine is from Frozenbyte and eventually came to Linux after various delays with the Linux work being done by IGIOS and Linux Game Publishing. They both are unique first person shooters.
Trine is a side-scrolling puzzle game originally released by Frozenbyte in 2009, then for Mac OS X in 2010, and now in 2011 with this bundle it's making the Linux debut. Jack Claw is an unfinished game right now that's described as "a never before seen prototype" and the Splot game is also still in development. All five games have native Linux clients, per the Humble Indie Bundle requirements.
As always, there's no embedded Digital Rights Management restrictions and you can optionally donate some of the proceeds to the Child's Play and Electronic Frontier Foundation (EFF) charities.
The two previous bundles have each generated more than one million dollars (USD) in proceeds and many of the past titles have been open-sourced. It will be interesting if that happens a third time, especially if Frozenbyte's Shadowgrounds games are, which run on a modified Storm3D engine.
HumbleBundle.com hasn't yet been updated for this third bundle, but it should be soon. In the mean time you can see the YouTube video for this "Frozenbyte Bundle" deal.