qooxdoo is a universal JavaScript framework for creating applications for a wide range of platforms. It has a comprehensive feature set, including an object-oriented programming model, an integrated tool chain and a state-of-the-art GUI toolkit.
Note:
Please note that as of 2011-10-26 the code repository for the project has been moved to https://github.com/qooxdoo/qooxdoo. The existing SVN repository will be set to read-only for the time being, and will not see any more updates.