PyDev is a plugin that enables users to use Eclipse for Python and Jython development -- making Eclipse a first class Python IDE -- It comes with many goodies such as code completion, syntax highlighting, syntax analysis, refactor, debug and many others. If you want more details on the provided features, you can check here.
Wicked Shell is an Eclipse plugin providing direct access to your system's shell. To be honest, Wicked Shell is not evil at all, although it calls itself wicked...
WSMO Studio is a Semantic Web Service editor compliant with the Web Service Modeling Ontology. WSMO Studio is available as a set of Eclipse plug-ins that can be further extended by 3rd parties.
WOW!!! Mylar is a task focused UI for Eclipse that makes working with very large workspaces as easy as working with small ones. It supports task management and monitors your work activity to identify information relevant to the task-at-hand. Mylar uses th