There's Aptana which is a really good IDE based one but for practical purposes you can always use a lightweight editor such as Emacs, ViM, or even Gedit or nano if you want to keep it simple. For what you're looking for Aptana sounds best.
As another person suggested Webstorm is also quite good (at least I've heard) the company I used to work for used it quite a bit and they loved it so that's worth a try although it is paid of course.