mnerv is a Python web application that provides an open 'Noun Space' for collaborative authoring of various, rich content types that may be interwoven. The concept of a 'Noun Space' is derived from the REST architectural style. Under REST, each segment (or noun) in a URL path should act as an identifier for a specific object. These segments are discoverable and otherwise traversable by humans and machines. For example, if a user types '/foo/bar/baz' into her location bar and no object is found, she is given an opportunity to create something new there. There is no requirement for objects to previously exist at either '/foo' or '/foo/bar'.
This is a long term experiment. It is not a wiki nor a CMS (antiquated terms that limit our willingness to conceive of anything different). It may share aspects of both, but due to its strong adherence to REST is usable by machines as well as humans.
There is a test instance setup at http://mnerv.appspot.com/ Feel free to add content with the caveat that someone may wipe the slate clean if need be.