Loren created YARD, which is easily the best Ruby documentation generator out there. His attention to detail and concern for release management is pretty much unparalleled within this community. He's also a recipient of a Ruby Hero award.

Full disclosure: Loren and I have collaborated on projects before. We co-authored the current version of rubydoc.info, the online doc host for Ruby gem and Github projects. So yes, I'm biased, but I've also seen the quality of his work first-hand.