The Telepathy API has until recently only been available as a single large HTML document. The HTML is generated from D-Bus introspection XML with extensions for stuff like enums. I hacked up a conversion to DevHelp's index format, meaning you can use DevHelp to browse the documentation.
To set it up:
- check out the telepathy-spec repository
- run make
- copy doc/spec.html and doc/telepathy-spec.devhelp2 to a directory /usr/share/doc/gtk-doc/html/telepathy-sp
This might also work for other D-Bus APIs; I haven't tried.
(If you're developing using Gtk/GLib/Cairo/Pango/GStreamer/etc. and not tried DevHelp, I heartily recommend it. It's really handy, especially with the Ctrl-S shortcut.)