Cappuccino - Desktop-Caliber Applications that Run in a Web Browser

Cappuccino is an open source framework that makes it easy to build desktop-caliber applications that run in a web browser. Cappuccino's AppKit ships with a huge number of controls, each polished far beyond what's expected on the web. Cappuccino is focused on making apps and the unpleasantries of building complex cross browser applications are abstracted away for you.