SproutCore brings the values of Leopard’s Cocoa to the web, domesticating JavaScript into a functional application platform with lots of free built-in support for desktop features.
Being based on open web standards and being open source itself means SproutCore will enable developers to develop cross platform applications without being tied to either a plugin architecture or its vendor.
Sitting on top of web standards will also make it easy for Apple and the community to push SproutCore ahead without worrying about incompatible changes to the underlying layers of Windows, a significant problem for the old Yellow Box or some new Cocoa analog. SproutCore also lives in a well known security context, preventing worries about unknown holes being opened up by a new runtime layer.