> YUI = huge(!), robust, pretty stable, great event handling, good
> documentation...
As Michael mentioned, you control the size by using just what you need, *plus* Yahoo provides minified versions, plus you can easily *GZIP* that. For example, the minified/GZIP'd version of the Event library is ~2KB.
Some older browsers have problems with _javascript_s sent over the wire gzipped (Netscape 4?). But who cares about them anyway :) They can use squirrel if they don't like to use new free stuff like browsers and web apps - our all new ZMail, for instance ;)
