Flexwiki

FlexWiki is an open source wiki engine.
Basic Features
- Easy editing; quick hyperlinking, tables, etc. - use simple FormattingRules to make editing easy and to convert simple text to HTML
- Get email when the wiki changes - A WikiNewsletter is a collection of topics and people interested in those topics; email is automatically generated to subscribers of a WikiNewsletter telling them about the changes to the associated topics. You can create a WikiNewsletter.
- RSS feeds - if you like RSS feeds for getting updated on information from various newsfeeds, you can track this wiki using an !!RssAggregator.
- Full topic history - anytime somebody changes a page, the old version is saved; by using the 'highlight changes' option, you can see all of the old versions; you can even link to them to get a stable reference. Selecting a simple checkbox is all it takes to visually show what changed in a topic from version to version.
- Topic search - type in a search string (using regular expression if you want); see all the wiki topics that match your search -- including content fragments from those topics
- Back links - you can click on Find References in the left column and you'll automatically perform a search to find all topics that reference the current topic
Advanced Features
- WikiTalk - a dynamic language for processing and inserting dynamic content into Wiki - Federation and namespaces - When there are many somewhat related Wiki sites, it's often hard to get them to link together smoothly. FlexWiki has some very cool features to support this scenario. Specifically, a single installation of FlexWiki (called a WikiFederation) can bind together multiple WikiBases. All topics in a WikiBase live in a TopicNamespace. See WikiFederationOverview.
- Page properties - WikiPageProperties are fields on a page like Keywords, Summary, etc. are recognized as properties of the page and can be used for various things including IndexingWikiContent, ExtractingWikiContent, building WikiNewsletters, etc. To use a page property on a page, see PropertyBehavior.
- Easy (no so) integration with search engines - all content on this wiki is indexable by search engines. For details, see IndexingWikiContent
- Optimistic locking - If you're editing a wiki topic and somebody else saves a change to the same topic, you'll be told; you won't be able to overwrite their changes
- Automatic plurals support - If you define a wiki topic using the singular form (e.g., BigDog), plural forms (e.g., BigDogs) will automatically link to the singular form (unless somebody explicitly creates a topic with the plural name too!)
- Dynamic content - A number of WikiBehaviors allow you to add dynamically-generated content to a wiki topic.

Go to http://www.flexwiki.com/

See also these related projects.