gtk-doc in Yelp
After finally pushing upstream some Yelp and gnome-doc-utils patches, and Shaun fixing some other bugs, a pristine Yelp can display the Docbook generated by gtk-doc. To prove it here is a screenshot of Yelp showing the Loudmouth API documentation.
It's not yet perfect: some elements need more styling and links don't work properly yet (not sure what the problem is there though), but it's a promising start.