Is there somewhere that I can get a definitive list of what is and is not supported in Eclipse's JSDT Javascript support?
The documentation supplied with Eclipse is quite sparse. I'm particularly interested in what JSDOc tags are supported and where, as my experimentants are producing rather confusing results.
I'm also interested in details of the other features (completions, refactorings).
Googling hasn't produced anything useful
I know this question is old, but I'll try to provide some useful information. There is no one single place to find this information. My understanding is that JSDT is only casually maintained at the moment. For Eclipse Indigo, there have been improvements for rhino support, but there is not much work on core JS features.
There is some documentation included with Eclipse help: http://help.eclipse.org/indigo/index.jsp?topic=%2Forg.eclipse.wst.doc.user%2Ftopics%2Foverview.html
There are also some feature descriptions in the new and noteworthies:
And a list of older releases is here: http://www.eclipse.org/webtools/development/news/main.php
Hopefully this helps a little.