Vim is a text editor.
It edits text.
 Editing XML (dix, transfer rules) in vim
http://www.pinkjuice.com/howto/vimxml/ is a nice guide to editing XML in vim
 Editing Xerox formats in vim
Various people have created lexc/twol syntax files for vim:
- https://github.com/flammie/vim-finitestatemorphology (works with vundle as flammie/vim-finitestatemorphology)