World of Goo Releases Rapid Prototyping Framework
2dboy.com
2dboy.com
Someone should port it to Linux and OS X, or at least have some instructions for those platforms. I'm sure it will work on those, as WoG is available.
Also: If you even mildly enjoy casual games, I would highly recommend playing and/or purchasing World of Goo. It has wonderful artwork and a some very nice pop-culture critiques between the lines.
For the record, it's 2D Boy that released the framework, not the piece of software World of Goo.
http://love2d.org/ is a similar wrapper around SDL, but you script it using Lua.