Isolator is a project mainly written in OBJECTIVE-C and C, it's free.
Make all non-foreground apps dim. Not my app, this code mostly belongs to Willmore.eu (http://willmore.eu/software/isolator/)
Isolator was originally written by Willmore: http://willmore.eu/software/isolator/. I’m cleaning up the project up a bit: it needs to build with a newer version of Sparkle, and needs to move off some private APIs to successfully build for 64-bit on Snow Leopard.