Following is an alphabetical list of known wikis or other websites making use of the WikkiTikkiTavi engine:

Site Use of WikkiTikkiTavi
http://www.accra.nl Community site for Aiesec trainees who have been in Ghana
[AllMyFAQs WBT Project] 'Tavi author view (passworded), non-wiki student view of tutorials
[Avisynth] Avisynth development & documentation
[Blackbox] The official site of the Blackbox window manager
[BlubNetWiki] Just a fun wiki for a group of friends
http://bronco.innra.net/ Site in Iceland logging Ford Bronco 1979 restoration.
[Byte Internetdiensten] Documentation System for ISP (Dutch)
[Bzzware] homepage of bzzware
[CaffeinatedWiki] Fun wiki with repository of a few HOWTO documents
[Circle.ch]  
[CodeBrewWiki] CodeBrew (an Open Source SourceForge project) support/discussion Wiki
[Colibri67] Discussion and presentation site for an association in Strasbourg / France
[CSS-discuss] A companion to the CssDiscussList mailing list
http://www.debianforum.de/wiki/ The Wiki of debianforum.de, a support website aimed at german speaking users of Debian
[Defoam the Net ] 
[Devipedia] Being used for a Development Dialog and to compile information about development organizations and activities
[Dimensional Rift Wiki] Dimensional Rift is a site for both public and commercial software and artwork. We use 'Tavi for the online documentation
[etree.org] etree.org is a collection of ftp sites that help spread legal, lossless music through the use of ftp sites. We are using the wiki in hopes that it will replace the current etree.org web site.
http://wiki.e-tropolis.nl/ Documents on software enigineering. Documentation on simulation frameworks, Object relational mapping and more
[FamilyNetWiki] Wiki for the FamilyNet II Computer and how to make it a HTPC
[Geekido]Personal page, working on some philosophy and tech tips content.
[Icesus MUD] A non-profit game project uses Tavi for development documentation, planning and a general idea repository.
http://wiki.infogroep.be/ Computer science students at the VUB, Brussels, Belgium.
[Informatik Potsdam] Computer science students in Potsdam, Germany. Uses a hacked version of Tavi with a main menu and dynamic side menus.
[InfusionWiki] For discussing and documenting projects of all types and for recording little tidbits of information.
[Inter\Face Magazine] Electronic Literary Magazine
[IR3IP Hamradio Website] A source for Amateur Radio projects and doc
[Juneau Wireless] Community based Wireless project in Juneau Alaska
[LTASH Personnal Page] A wiki for my personal pages : Chess, Music, Linux, ...
[LogiLogi.org] A modified version of Tavi featuring Multilanguage and Sections
[MACCAWS ] Developing a resource kit to Make A Commercial Case for Adopting Web Standards
[Midnight Squadron Kite Tips]A portion of the site uses a Wiki for kiters to share tips on flying.
[NarcFishNewtonSoftware] A (tiny) collection of software and resources for the Apple Newton -- an experiment in using a non-publicly editable wiki as a general web site.
[NetartMagazine] An italian wiki about webdesign.
[NewtWikiWiki] Wiki supporting NewtWiki, wiki-like automatic hyperlinking software for the Apple Newton.
[nkoni.org/daniele ]Personal page, RSS,jabber, personal development..lots of things, used as an online notebook.
[Nomic Wiki] A Wiki I created to play a game of online Nomic. - Silly
[OffeneBibliothek] Open Library Project, Germany, this is german
[Open Office] Open Office uses WikkiTikkiTavi for its intranet wiki
[Palimpsest] Experimental comedy
[PalmGrachtWiki] Wiki for a neighbourhood in Amsterdam, the Netherlands
http://www.pgaccess.org/ The prettiest GUI for PostgreSQL.
[phpGroupWare-docs] documentation/support/discussion [phpGroupWare] (a GNU groupware project)
[phpportalen.net] Swedish PHP forum, Tavi is here used in a "tweaked" version. Easy to do and good looking.
[ProjetWikira] A French collaborative wiki novel in the field of the science fiction
[Russell Freedom] Please pass the porridge.
[Salim Fadhley] Personal blog and Wiki
[Smarty Wiki] Wiki about the PHP Template Engine [Smarty]
[SquirrelMail] Runs version 0.20 for project documentation and support
[Wiki Tutto] My personal wiki pages, pretty css customized and integrated into wordpress stylesheet
[Tea Drinking Monkey] A political blog with an attached wiki for collaborative documentation about political stuff. We've even employed a cute hack to the blog so CamelCase entries link straight to the wiki!
[UGCA Wireless] A Community Wireless Internet Project.
[unux.org] French site for Linux beginners
[unit-sound.de] wiki about analog synthesizer
[UTWorld taviWiki] Building the first wiki guide for outsports in China. It's the sister wiki of [UTWiki]
[VEMS] A Wiki for a DIY EFI controller. All public development!
[WdteProjectWiki] Wiki for the Web Development Tools for Eclipse project
[WikkiTikkiTavi] Runs (approximately) the 'Tavi CVS, presently version 0.25
[WikiWikiWireless] Red libre inal¨¢mbrica, Comunidad wireless en español
[XdebWiki] Part family- and part test-wiki. Mostly in Swedish.
[YawtbWikiHelpPages] The help pages of the YAWtb, for Yet Another Wavelet Toolbox
Please try to insert your Wiki site alphabetically, either according to the name or URL.