Earlier quoted context omitted.
Some of the server-side JavaScript stuff is really slick. APE ( http://www.ape-project.org/ ) runs JavaScript on the server-side, for instance. You basically write a client and server in JavaScript and it uses Comet to push events to the client, rather than a JavaScript client needing to constantly request updates -- a great paradigm, that could lead to much more robust multi-user JavaScript applications.
"Helma" Framework comes to my mind too: http://helma.org/
I had it downloaded about a year ago and made a few toy projects, but nothing serious enough to really give it a proper workout. (And I don't have a VPS to actually launch anything on...)