Hope this fits this forum topic.
I have been playing with Dokuwiki and ProjectPier, and created a page with an explanation on how to have dokuwiki authenticate with ProjectPier users. It works (oh yeah!) in very basic form, meaning you need to manage users and passwords in Pier, and not in dokuwiki, but not a big problem for me.
So now one can login in the wiki using his Pier user/password
This was based in the dokuwiki+gallery2 example in dokuwiki site, so I thought of adding what worked for me in the link bellow: