All of the games work great on Mac, Windows, and Linux.
We don't use DRM. When you buy these games, they are yours. Feel free to play them without an internet connection, back them up, and install them on all of your Macs and PCs freely. There is no time-limit on your downloads.
You can support charity. Choose exactly how your purchase money is divided: Between the game developers, the Electronic Frontier Foundation, or the Child's Play Charity. Also, if you like this deal, a tip to the Humble Bundle itself would be much appreciated!
How much is this bundle worth to people? Let's take a quick look.