Wagn: A Revolutionary Open Source Wiki on Rails
Everyone knows how wikis work by now - but when was the last time you saw a wiki that struck you as advancing the state of the art? Despite scores of implementations, most wikis are similar to the original. But the Wagn project is trying to change this - and using Rails as its infrastructure.
The basic innovation with Wagn is that instead of the editable units being pages, they're cards - and cards come in many different types, each with their own properties. So there are basic cards with a rich-text editor, HTML cards, plain text cards, image cards, executable Ruby cards, user account cards, and more. In addition, it supports "plus cards" - linkages between other cards that let you assign tags or attributes or indicate how other cards combine into tuples. The effect is a sort of cross between a wiki and a database.
Other features include the ability to nest cards within other cards, dynamic form building, a permissions model, and WQL - the wiki query language - which lets you build up flexible cards through searching for other cards.
The source for Wagn is available on GitHub, and it's under active development. If you've got a reasonably sophisticated user base, it would be a great alternative to a more structured CMS for many sites.