Highlights corresponding PHI data in the text portion of an i2b2 XML Document.
i2b2-mode is in the MELPA repository! So you can use package.el to install it.
You can always manually clone it and add it to your load path if desired.
This is the code I use to load it:
(add-hook 'nxml-mode-hook (lambda(&rest args) (require 'i2b2-mode) (if (i2b2-buffer-p) (i2b2-mode 1))))