The Google Web Toolkit looks cool. Now we know how they do it.
You write your front end in the Java programming language, and the GWT compiler converts your Java classes to browser-compliant JavaScript and HTML.
A couple of weeks ago I was thinking about a similar (at a very high level) approach in Python. But now that we have something to imitate, anyone interested in trying to build a more specific Python equivalent? Portions of the GWT are open source and nothing in the license prohibits reverse engineering as far as I can tell.
I'll set up a mailing list for interested people.
UPDATE: Mailing list available at http://pyworks.org/mailman/listinfo/py-gwt
UPDATE (2006-05-23): Now see Primitive Python Version of GWT Working