Sputnik is a content management system (CMS) designed for extensibility. It works as a wiki out of the box, but can be extended into other things. It offers editable nodes, history and diff, user accounts with optional email validation, a flexible permission system, RSS feeds, and more. Sputnik supports access control and has editable templates. It can be used to maintain a personal Web site that doesn't look like a wiki and that only you can edit. Sputnik is easy to install on shared hosting without root accounts.
Hatta is a small wiki engine for use inside a Mercurial repository. It can run locally and doesn't require any configuration; it's just a single Python file. It can be also configured to run on a Web server. Since the wiki can be cloned and merged along with the repository, it's perfect for working on project documentation in small teams.
Piggydb is a flexible and scalable knowledge building platform that supports a heuristic or bottom-up approach to discover new concepts or ideas based on your input. You can begin with using it as a flexible outliner, diary or notebook, and as your database grows, Piggydb helps you to shape or elaborate your own knowledge. Piggydb is a Web application provided as a self-contained package that contains a Web server and database engine.
Synoptic is "GMail for your notes", meant to keep and categorize a large number of smallish notes and tidbits of information. Tagged overviews that retain order make it easy to maintain a good overview of your things. Adaptive tag clouds plus integration with browser bookmarks and forward/back navigation allow for easy navigation. Written in pure Python, it runs as a local Web server.
uWiki is a minimalistic wiki engine. All actions are implemented in external scripts. These scripts are wikified, and thus the wiki is extensible by itself. All dynamic access is protected through ACLs. Wiki content and Web content can be mixed in the same directory hierarchy. Markup engines and revision control are plugin-able. Currently, asciidoc as the markup engine and git as the revision control backend are provided. Subdirectories can form independent sub-wikis with own revision control. Features like distributed pages that syncronize between wikis, spam protection, and batch jobs to schedule mirroring of other content (bittorrent, git, rsync, and wget) are in planning.
PMwiki is a wiki-based system for collaborative creation and maintenance of Web sites. 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 Web site, 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. Running PMwiki as a JumpBox allows you to be up and running with this software in minutes on any operating system. It carries other benefits such as portability across computing environments, a Web-based admin console to simplify administration, and a built-in automated backup system to protect your work.
WAscii is a Web frontend intended to display an AsciiDoc documentation repository. It allows you to search and browse your documentation files and automatically converts AsciiDoc to HTML, PDF, and ODF documents. It is intended to work directly from a subversion repository containing your AsciiDoc files.
Trac is an advanced tool for managing software development projects. It provides a simple wiki, an issue tracking system, and tight integration with the Subversion revision control system. However, it's also notorious for being hard to install. With the JumpBox for Trac, it takes about a minute to get trac running. Plus, with the built-in subversion and database backup system and the JumpBox Web-based administration console, it gives you all the basic tools you need to put it into production without ever touching a command line.