> I just glanced at the online manual at docbook.org, however,
> and it looks pretty complex.
I'd call it "full featured" instead. Yes, DocBook
has enormous support for all sorts of constructs,
like those you'd see in a meter of shelfspace of
manuals from a major hardware vendor. But you
don't have to use all those features. And with
a smart SGML/XML editor (like psgml in emacs) to
guide you, using it's not that hard.
Also note that the FreeBSD documentation project,
Linux documentation projects, and O'Reilly &
Associates publishers all make use of it, so you're
definitely among open-source friends.
It might not be de facto yet, but it's getting
there. Like Ant.
--k