Coffeescad

Parametric modeling tool similar to OpenScad, but running in your browser, using a Coffeescript base & syntax :
this means support for classes, real variables, advanced iteration etc )
and a better code editor! (line numbers, syntax highlighting, search & replace ...)

Update : august 2013
The project has grown a fair bit, website is now at http://coffeescad.net
and you can give the latest version a try here :
http://coffeescad.net/online_edge/