What do you want to know? :-) ¦·)
Some prefer Python. However, client-side editing requires neither http://www.python.org/ Python nor [(approve links) edit diff]. A lightweight server-side interface to local http://www.tiddlywiki.com/ TiddlyWiki files could quite possibly result in a halfway decent peer to peer style of collaborative document-sharing. This could be done via email.
Alternatively, server-side software could store web-facing documents, and also act as a link node for authenticated users and peers connecting from anywhere. Thus they could collaborate publically and privately with ease.
Personally, I also like the idea that page mark-up could be defined using a wikipage, such that different pages could use different mark-up, depending on the parse-preference of the author. This would be done using a link on the page to the mark-up definion page. Pages written using one wiki server or another would not requuire mandatory mark-up changes to be converted between wiki servers. Additionally - and this is one of my favourite motivating factors - one page could be parsed by more than one mark-up page. The result could be pages served in arbitrary formats, from .ps to .svg to .(x)html and so on.