which is a full implementation of the Cocoa framework and Objective C for the web. Code that you write for a Mac can with little effort also be used on the web with this framework.
is a framework created by Sproutit for their mail application, and then open sourced. Apple now uses it in their new MobileMe web apps. SproutCore has MVC - Module View Controller - archetecture much like Apple's Cocoa.
Examples of Applications 280 Slides is a presentation application created by 280 North with objective-j. It looks like Apple's Keynote, and for a good reason - objective-j is based off of Cocoa and objective-c. Very impressive. (This presentation was made with it!) MobileMe is the successor to .Mac from Apple, and it includes new web apps developed with SproutCore. The apps look very much like their desktop counterparts, and act like them too. They have drag and drop, live updating interfaces. Only problem - $100/year!