Wiki Perl module published at CPAN.

A Perl toolkit for developing wikis.

A wiki clone "for regular people", based on templates and designed for ease of localization.

A wiki engine designed for modularity and easy installing.

Proprietary, commercial implementation with Javascript page-editing front end. Also available as a hosting service.

Modularized descendant of UseModWiki with limited weblog support, used on Technomanifestos.net (GPL).

Heavily featured variant, with revision control, templates, category tables, authorization based on groups, automatic email notification of changes, file attachments.

A single-file implementation of the original Wiki concept created by WardCunningham. With flatfile database and numerous patches to extend feature set.