PHPWiki - Feature-rich implementation with support for various databases. MediaWiki - Wikipedia's underlying open source wiki engine. Particle Wiki - A light PHP/MySQL wiki engine with archived history, search, admin panel and skins (released under proprietary Particle Soft End User Licence). WikkaWiki - A free PHP/ MySQL wiki engine based on forked code from WakkaWiki. Includes a GUI page editor, advanced syntax highlighting and mindmap support. Released under GPL. PmWiki - A simple-to-install system which allows password protection and organization of pages into groups (GPL). Semantic MediaWiki - Popular extension of Wikipedia's wiki engine with Semantic Web features, enabling better search and organization of wiki content. Elaborate - A free wiki engine written in PHP and MySQL available under the GPL. Site contains source code and documentation. Wacko Wiki - Small, lightweight, handy, expandable, multilingual Wiki-engine based on Wakka Wiki. WYSIWYG editor, easy installer, many localizations, email notification on changes/comments, several cache levels, design themes (skins) support, XHTML compliance, page rights (ACLs), page comments. LionWiki - A minimalist wiki engine that is file-based and is encoded in a single document. Site contains downloads, a roadmap, as well as some plugins and templates. Tiki - A kitchen-sink content management system that combines wiki with a Slashdot-style article system, blogs, forums, image galleries, chat, and so on. Pear:DB backend, LGPL. Wiki Web Help - An AJAX based wiki engine designed to operate similar to a desktop help viewer. Anwiki - A wiki/ CMS dedicated to multilingual contents. Wikepage - A small dual-mode wiki engine that can act as wiki sites and personal homepages.