Formatting template text

I’m pretty sure I’ve seen this sort of thing referenced before. I’m on the lookout for a module that would make life easier while composing code in templates, mainly, one that would allow for text formatting similar to Textwrangler, Dreamweaver or Notepad++ (especially use of the TAB key). I realize I could just edit my code in one of these programs, but all the copying and pasting could get messy. Please let me know if anyone knows of such a module, or feel free to tell me if there’s no such thing!