Dojo is the Open Source JavaScript toolkit that helps you build serious applications in less time. It fills in the gaps where JavaScript and browsers don't go quite far enough, and gives you powerful, portable, lightweight, and tested tools for constructing dynamic interfaces. Dojo lets you prototype interactive widgets quickly, animate transitions, and build Ajax requests with the most powerful and easiest to use abstractions available. These capabilities are built on top of a lightweight packaging system, so you never have to figure out which order to request script files in again. Dojo's package system and optional build tools help you develop quickly and optimize transparently.

Dojo also packs an easy to use widget system. From prototype to deployment, Dojo widgets are HTML and CSS all the way. Best of all, since Dojo is portable JavaScript to the core, your widgets can be portable between HTML, SVG, and whatever else comes down the pike. The web is changing, and Dojo can help you stay ahead.

One of the advantages of using a library is that someone else has though about optimisation for you. So for us, the library authors, we need to know which is the fastest way of doing things in our target environments. The best way to get an idea of the speed of things is to benchmark, so introducing a benchmark suite allows us to evaluate the performance of particular ways of doing things.

Dojo makes professional web development better, easier, and faster. In that order. "Get it here"