I have to edit lots of grammar files in .bnf format. Is there a mode for this in Emacs?

I've looked at CEDET's semantic package, and it seems that it USED to have a bnf-mode, but not any more. This snippet is googlable, but semantic-bnf-mode doesn't seem to exist:

```
(autoload 'semantic-bnf-mode "semantic-bnf" "Mode for Bovine Normal Form." t)
(add-to-list 'auto-mode-alist '("\\.bnf$" . semantic-bnf-mode))

```