I've uploaded updated renderings (pdf or png) of the document I use to keep track of the non-trivial, public DHTML toolkit efforts that have occurred over the years.
Interestingly, the difference between this version and previous ones is that many companies are starting to either release or talk about tools that they had quietly built in-house years ago. Also, Google and Yahoo have been on something of a hiring binge. Yahoo seems to be dedicating more (visible) resources to their responsive UI cause than Google. The secrecy difference between the two cultures might explain the delta, but I'm convinced that's not the whole story.
I will admit to not having kept this document as up-to-date as it should be. The proliferation of toolkits over the last year has been pretty astounding, and investigating each one to find out if it's just another crappy 10-line XMLHTTP wrapper hasn't been on the top of my list of things to do. So in true open-source style, your help is requested! If you have corrections or new information, please either mail them to me or submit a patch to the graphviz source file. The format is straightforward and easy to figure out.