It's not general purpose, but colorforth has a really weird and different editor. Coloring words "types" the word (definition label, compiled, immediate, comment, etc), which allows the language and compiler to be dead simple. It really makes me wonder why modern languages aren't designed with IDEs in mind - instead of loading the syntax with complexity, separate it out into the fancy editor layer! Color/text formatting is probably not the best paradigm, but the potential of editor-first language design hasn't really been explored anywhere near as far as it deserves.

As far as conventional editors go, I'm a big fan of vis. Multiple cursors, structural regex, and vi keybindings are just too nice to give up.

https://github.com/martanne/vis