IMHO, if you need an editor with paren-matching and auto-indenting (and maybe even syntax highlighting) just to make working with your language tolerable, that's a possible design flaw in the language.

I know it's heresy in a Lisp thread to claim that it's possible for a language to have too little syntax, but I can write Javascript, C and C++ just fine in Notepad or Sublime Text if I want.