Pyle is a WikiClone written in Python. I wrote the original version in 1999 after exposure to Ward Cunningham's original WikiWiki perl script. In the years since, it has sprouted support for a number of interesting features, and has been a major part of the intranets at eServGlobal and also at LShift, where it's still in use.
Earlier versions of Pyle had extensive installation and configuration documentation, but for now, the best that's available is the source code itself.
Versioned document and attachment store, backed by either a plain flat file system or by CVS, subversion, darcs, or mercurial
Interesting extensible markup language that plays nicely with emacs'
Support for attachments, backlinks, bugzilla links, enscript-based syntax highlighted source code, footnotes, graphviz
dotdiagrams, embedded HTML, page transclusion, message sequence diagrams, tables, etc.
Customisable user authentication (with support for authenticating against a bugzilla instance) and user/group-based access-control mechanism
Automatic "pagerank"-like hierarchy/table-of-contents/sitemap generation
Email notification when a page is changed
Modular templates make extensive customisation of the wiki's appearance possible
Pyle is hosted on github.
A couple of very old, unmaintained, historical versions of Pyle1 are available: