Ask DN: Best examples of professional style guides?

over 9 years ago from , Web Designer/Developer

I am very interested in learning what DN thinks are the cream of the crop in terms of professional "style guides" for a site/web app.

A few examples that I am keen on: GitHub's styleguideYelp's stlyeguide

And, on an interesting note, Mail Chimp's multi-part guide for writing and patterns: Style Guide for writing/bloggingPattern Library, or what others call a styleguide

Of course all three have separate pages for brand assets and the like.

So, if I were to set out to make a combined code/visual styling guide in the vein of GitHub and Yelp, are there any other major examples of a clean and cohesive style guide that I am missing?

P.S. Maybe the most important question, is it one or two words?