Brian McCallister has done a plugin for
A new-format language "mode" for SubEthaEdit 2.x is available
VIM has been done by Alessio Pace
A language specification for Apple's
Guillaume Laforge wrote a syntax file for the TextPad text editor which can be downloaded
Jeremy Rayner has written a groovy-mode for emacs, details of which can be found on the Emacs Plugin page.
Russel Winder has started an alternative to Jeremy's based on CC Mode (Jeremy's was reworking of ruby-mode). Also Stuart Clayman has created a Groovy execution mode. See the Emacs Plugin page for details.
Find more info on the UltraEdit Plugin page.
Syntax files have been created for