Photoshop ships with libraries for VB and Applescript so that you can search for methods and commands and add them with a click from within the editor. But the only Javascript reference I can find for PS is the PDF. Is there some sort of JS library for Photoshop that can be accessed by one of the dedicated JS editors out there?

This is one of the better searchable PS DOM sites:

http://www.phrogz.net/objJob/objects.asp?langID=9

The PDF from Adobe is still the best for seeing and learning how things fit together.

That's a very handy resource, thanks.