Showing software for all platforms
TikiWiki is a Groupware/Content Management System solution with a long list of features to help you build a compelling Web-based community: wikis, forums, blogs, articles, an image gallery, a map server, a link directory, translation, internationalization, and much more. The JumpBox for TikiWiki gives you a chance to try it with minimal effort. The JumpBox has a built-in Web management console to help you manage basic system tasks and a very convenient backup system to make sure your data is safe.
Foswiki is a wiki that supports the embedding of active and passive macros that enhance page content (e.g., with global and/or dynamic information) and allow end users to build applications that store and process data in a structured manner. It is a fork of Twiki.
PmWiki is a wiki-based system for collaborative creation and maintenance of websites. PmWiki pages look and act like normal web pages, except they have an "Edit" link that makes it easy to modify existing pages and add new pages into the website, using basic editing rules. You do not need to know or use any HTML or CSS. Page editing can be left open to the public or restricted to small groups of authors.
MediaWiki is the wiki used by Wikipedia. It's powerful, scalable software that's designed to be run on a large server farm for a web site that gets millions of hits per day. Pages use MediaWiki's wikitext format, so users without knowledge of XHTML or CSS can edit them easily. When a user submits an edit to a page, MediaWiki writes it to a database, but without deleting the previous versions of the page, thus allowing easy reverts in case of vandalism or spamming. MediaWiki can manage image and multimedia files, too, which are stored in the filesystem. For large wikis with lots of users, MediaWiki supports caching and can be easily coupled with Squid proxy server software.
MoinMoin is an advanced, easy-to-use, extensible wiki engine with a large community of users. It stores information in flat files rather than a database, and is relatively easy to set up. The software supports plugins and CamelCase linking.
OpenWiki is a quick and easy way to post your thoughts to the web from anywhere and retrieve them again. OpenWiki can be collaboratively edited, by anyone or a selected few, using a web browser. Content can contain rich text and hyperlinked notes. The software requires Active Server Pages (ASP), so runs only on Windows hosts.
PhpWiki is a clone of WikiWikiWeb that supports multiple storage back ends and dynamic hyperlinking. The software is themeable, and scriptable by plugins. Security features include full authentication and access control lists (ACL).
TiddlyWiki is a single HTML file that has all the characteristics of a wiki, including all of the content, the functionality (including editing, saving, tagging, and searching) and the style sheet. Because it's a single file, it's very portable - you can email it, put it on a web server, or share it via a USB stick. It has powerful plugin capabilities, so it can also be used to build new tools. You have full control over how it looks and behaves.