Olympos is an holistic MDA/MDD approach to projects. It allows to create Web (PHP, J2EE), Desktop (c#) and Mobile applications (.NET, J2ME) from a UML model. Features a Web 2.0 IDE, a generator based on openArchitectureWare and several cartridges.
JS/UML is a plugin for the Eclipse IDE that reverse-engineers JavaScript code to a UML model which can then be used to generate documentation and other artifacts.