I’m not aware of anything right now for emacs or any other editors. SenseTalk (like all xTalks) is an unusually context-sensitive language, in which a single word may mean different things depending on where and how it is used. This makes syntax coloring more difficult. Eggplant achieves its syntax coloring by calling the SenseTalk compiler, which isn’t really an option in other environments.
However, although you’re not likely to get full syntax colorization in another editor, it should be possible to create an editing mode that would recognize some key words, and especially structures like handlers, repeat loops, and try/catch blocks. If anyone finds or creates such an editing mode, please let us know.