Aptana Studio
http://www.aptana.com/products/studio3
Plugins
- jshint-eclipse - JSHint integration for the Eclipse IDE
Code Completion
- jQuery: Commands->Bundle Development->Install Bundle and then select jQuery from the list.
Validation
- We've added a new high-performance JavaScript Style validator that does much of what JSLint does, but in a fraction of the time. Try turning it on in Preferences > Studio > Validation > JavaScript.