I guess it is part of syntax highlighting, but what about error/style highlighting?
For example - I love Eclipse for writing Java because it also gives errors/warnings highlights next to the code, and also style advice if you ask it too, so you don't even need to rub the code to find errors. I guess sometimes it can be too much (like that paperclip that everyone hates), but i find it very useful because i don't spend the majority of my time writing java.
Maybe an IDE that supported perlcritic || perltidy would be useful too.
Just a something something...