I was thinking today about WebObjects, after reading this on osx.macnn.com:

So, go to the ADC site, join the program, click on downloads, and have a blast. Interface Builder and all the other OS X tools await you! (Well, WebObjects is not free, but still...)

It reminded me something I wrote earlier this year. It's worth reading again, I think.

WebObjects is free -- updated with a link to the WebObjects Overview movies on the WO training site.

Here's a really old article by David Neumann, a very talented and respected WebObjects developer who used to work on WO at NeXT and then Apple and now works for Valicert, IIRC.

An Introduction to WebObjects