rdoc-tags

https://github.com/rdoc/rdoc-tags

A TAGS file generator that builds both vim and emacs style tags files. Vim tags are based on http://ctags.sourceforge.net/FORMAT). rdoc-tags is compatible with Exuberant Ctags for merging tag definitions. rdoc-tags includes a Hoe plugin +:rdoc_tags+ making it easy to add tag support to your ruby project. If you don't use Hoe you can instead use RDoc::TagsTask to add rake tasks for building TAGS to your ruby project.