TightWind is written by Kyle Baxter. Stay Hungry. Stay Foolish.

Sean Heber and Craig Hockenberry built Chameleon, a port of iOS’s UIKit to Mac OS X:

If you’re an iOS developer, you’re already familiar with UIKit, the framework used to create apps for the iPhone, iPod and iPad. Chameleon is a drop in replacement for UIKit that runs on Mac OS X. In many cases, your iOS code doesn’t need to change at all in order to run on a Mac.

They’re trying to make it easy for developers to move iOS applications to the Mac. This is rather incredible.