Our server spits out HTML and JavaScript. Generally, JavaScript is powerful enough to do what we want, and if it's not, then we either don't do it that way, or we submit the page to a PHP script to do it. Development time is actually quite quick - more so if you have a framework building things like navigation bars (we wrote our own).

I wouldn't even consider ActiveX. We considered a Java applet for new email notification, but that A Ways Off.

Wade.