Syntax highlighting is great...a minor tweak or request.

In javascript I'm using {}, [], and (). The first and last can look the same. It would be nice to specify different syntax presentation for the different delimiters.

I thought a solution might be some ability to specify "custom" tags. User could name the tag(s) and apply formatting and create the rule, etc. So for me I would have 3 custom rules:
Rule 1
tags (,)
color = red

Rule 2
tags {,}
color = blue

Etc.

I would start, then, by selecting a better font. There are good programmer's fonts out there that greatly help with these sorts of issues. See these threads for some pointers to available fonts and how to use them:

other-fonts-t112.html
interface-look-t3768.html