AOLserver Wiki
The official wiki web for AOLserver, America Online's open-source web server.
Bookshelved Wiki
A wiki dedicated to books; an online discussion where the primary topic is books read by the people who contribute.
CommunityWiki
For discussion of communities, both online and in the real world, including management, teaching and conflict mediation.
Crazy Hacks
A database of crazy software- and hardware-projects of geeks all around the world with way too much spare time on their hands.
Gaboons.com
A public wiki about participatory sporting events such as marathons and triathlons.
KmWiki
Large wiki about knowledge management with many resources.
Legjoints
Login based site covering a variety of topics as chosen by it's users.
MassMind Personal Computer Technical Reference
A wiki-like site that allows anyone to post new information, with page ownership and editors to keep things organized and tons of PC and embedded controller engineering information.
Public Wiki Forums
The possibly canonical list of public wikis, on the original wiki.
SVG-wiki
Resources and links for the Scalable Vector Graphics community.
TourBusMap
Central staging point for the "Tour Bus" system of routes between similarly-themed wikis.
Unmaintained Free Software
A GNU FDL-licensed wiki of unmaintained/orphaned Free Software projects which are in need of a new maintainer.
Wikipedia
The biggest multilingual open access encyclopedia on the internet. Over 500,000 articles and still growing.
Wine-Wiki
A project geared to provide peer created How-Tos, tips, and documentation to users of the Wine application.