Submission + - Latest Humble Bundle Supports Open Source GameDev Tools (humblebundle.com)
The open-source programming language Haxe is strongly represented: three of the charities include the Haxe Foundation itself, OpenFL (recently featured on Slashdot), and FlashDevelop, the most popular open-source Haxe/ActionScript IDE. The fourth is Ren'Py, the Python-based visual novel engine used in award-winning games like Long Live the Queen and Analogue: A Hate Story.
The games themselves are Magical Diary, NEO Scavenger, Offspring Fling!, Planet Stronghold, and for those who pay $6 or more, Anodyne, Defender's Quest, Evoland, and Incredipede, as well as 6 soundtracks.
7 of the 8 games are cross-platform across Mac/Win/Linux, and all are DRM-Free.