I've implemented experimental and rudimentary support in Resyntax for custom #langs, including non-s-expression #langs. This allows a language to configure Resyntax's default suggestions on code written in that language, and gives Resyntax the ability to perform automated refactoring over files written in that language.
I'm looking for testers who have created their own #lang and have code written in it that they'd like to refactor in a manner that can be reasonably automated. If you've written a #lang that fits this description, and you're down to try something wacky, let me know and let's see if we can make it happen.