mootools is a very compact, modular, Object-Oriented javascript framework. Its unique design makes it extremely crossbrowser, easy to use, and a snap to extend with your own code. It comes with a choice of more than fifteen scripts, plugins and addons, including Effects (moo.fx) Ajax (moo.ajax), Dom Navigator (moo.dom), Drag and Drop, Sortable lists, cookies Manager and many more.

All the previous moo scripts have been made better, reorganized and extended to fully take advantage of the new architecture, even if it retains full compatibility with scripts written prototype-style. One of the big differences is The Element Extension: mootools infact, makes it possible for you to extend HTML elements with your own methods, to make your life easier, and your coding style alot cooler.

Mootools have taken the best of Prototype and jQuery, you can start by enjoying their download page where you can choose what to download and create your personalized download package, choosing between the different available Native Scripts, Addons and plugins, while the core library is just 2kb. Documentation is available to get started with the library, Jonathan Snook have written a tutorial on Drag and Drop using mootools.