JavaScript on Aptana

I looked for a way to first write JavaScript in an IDE. I found Aptana which looks like Eclipse with the Aptana plugin pre-installed. It's a lovely concept, providing JavaScript (and PHP) syntax highlighting and intelli-sense (or what it is called when you hit "."). The problem with Aptana is I see how to debug JavaScript in it. I mean, why would I want to do that anyhow where there is Chrome debugging of JavaScript?