SproutCore
Website: http://www.sproutcore.com
License: MIT License
SproutCore is an open-source JavaScript framework. Its goal is to allow developers to create web applications with advanced capabilities and a user experience comparable to that of desktop applications. When developing a SproutCore application, all code is written in JavaScript (including the view layer in 1.0). SproutCore, initially created in 2007 by Sproutit as the basis for their Mailroom application, is available under the MIT License.
Apple announced MobileMe at WWDC in 2008, noting that much of it was built using SproutCore. Apple has contributed greatly to the project as part of a Web 2.0 initiative. SproutCore is also used at iWork.com, the online extension of the iWork productivity software by Apple.
Latest stable SproutCore release is 0.9.23 and 1.0, a major milestone with significant improvements, is scheduled for release summer 2009.
SproutCore is sometimes confused with the Cappuccino Application Development Framework: unlike Cappuccino, SproutCore seeks to provide a partial, Web-based version of the Cocoa API, whereas Cappuccino seeks to provide a full Web-based version of Cocoa API as well as web-based version of Interface Builder using its own Objective-J language.