Vim

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/arnsholt/proiel-morphology/tree/master/vim
• https://github.com/flammie/dotfiles/tree/master/vim/syntax

See also http://wiki.apertium.org/wiki/Apertium-specific_conventions_for_lexc#Syntax_highlighting_in_vim