Syntax highlighting support for Web IDL files. Also supports doxygen-like commands in the comment blocks as supported by the widlproc tool.
For pathogen users just add vim-widl as a submodule to your bundle:
$ cd
$ git submodule add -f git://github.com/aldafu/vim-widl.git .vim/bundle/widl
If you are not using pathogen you can manually copy the files to the appropriate locations in your .vim directory.
Note for windows users: instead of .vim above use your profile path, e.g. "C:\Users\username\vimfiles".