DomAPI

Cross-browser/platform DHTML API for developing Rich Client GUI within the browser.

http://domapi.com/faq.cfm

http://www.theobvious.com/archive.html?041502

Semi-OpenSource. Appears to be free (as in Free Beer), and source is provided, but you can't distribute the code.

It wouldn't work for my case. I need the validation on the server for other purposes. That does sound similar, howevever, to some whacky DHTML library Shane Hathaway has been cooking up.

er, crud, I forgot to sign my comment. and I suppose I should link back to z2003-05-07-JeffreyOnZopeFormulator from which this is based. - Jeffrey P Shell