Yesterday in my quest for a calendar picker for Jistik, I came across mootools which is a lightweight javascript framework for building AJAX/Web 2.0 style applications.

Mootools is cool, but I want you to direct your attention to their download page! The guys at mootools have built a tool that lets you select which mootools features you want, compression style desired and builds the download for you. Also neat is how it automatically includes dependent modules, so you can't screw up your download.

Check it out.