MooTools allows the user to write flexible and classic cross-browser codes through its well documented and comprehensive Application Programming Interface (API). This is definitely not a framework for the novice beginner; rather it is a boon for the intermediate and advance developer. By virtue of being exhaustively documented, it is very easy to browse through and use. Another added advantage is that it is available under the Open Source License, which permits access and modifier rights at every step in the development process.
Another popular and powerful framework available for experienced users is Dojo. The biggest advantage which Dojo offers to the developer is the options of surfing through various complex web application requirements like grids, charts, 3D effects etc. apart from enhancing HTML capabilities. It has found wide spread acceptance in developing web applications on all forms like mobiles and desktops.
You can view some of the demos at: http://demos.dojotoolkit.org/demos/
Choosing one among the above frameworks is a tricky proposition. We recommend users to evaluate the above frameworks based on what they truly require as their development requirements – whether it is widget features, documentation requirements, free usage or above all, a truly top notch web application development experience.