Which Library to Use?

With all of the buzz around AJAX beginning to die down a little and people actually thinking about the best way to go forwards, this is an excellent article which looks at the four main contenders for providing function libraries. The ever popular prototype, the up and coming Dojo, Mochikit of which I know nothing and the very new Yahoo UI Library.

For a long while now prototype has been my library of choice, it is relatively lightweight and does everything that I have needed. However I have been playing with Dojo and barring some misgivings about its size (a whopping 142kb for the AJAX version) the functionality is incredible and now that IBM has weighed in behind it who would bet against it becoming the de facto standard?

Anyway, if you are a web developer and you don't know much about these libraries then read this article, it's a great intro and also does a good job of comparing the different options in an unbiased manner. For the moment I think I'll be sticking with prototype but if/when the size of Dojo gets even more configurable I'll definitely be taking a closer look.

What are other people going for?