Since someone asked about these, I decided to make the raw files available for anybody that wants to play with them. These were written to work with XEmacs so anyone wanting to use them with GNU Emacs will probably need to change a few things.
Right now, these don't do much more that colorize the buffer. I hadn't figured out what kinds of things would be useful in an EXPRESS, EXPRESS-X, or Part-21 mode. Feel free to modify these to do other useful things. If you send your changes back to me, I'll post the revised files here for others to use and include your name as a contributor.