A major mode for editing Cg, This is a basic version of the mode, but should be useable. I encourage people to work on it!
Available at: Lisp:cg-mode.el
One way to load this, add to ~/.emacs (or see LoadPath):
(setq load-path (cons "/home/user/directory-with-cg-mode" load-path)) (require 'cg-mode)
By default it is used for files with the .cg extension.