Ross Mayfield heads SocialText, a social software firm best know for its wiki products.  We asked his views about these innovative collaborative tools.

There is lots in the press today about wikis. What are they and why are they cool?

A wiki is the simplest way for a group to create a website. Think of it as a multi-dimensional whiteboard that makes links easier than any other tool. Wiki Wiki means "quick" in Hawaiian, something Ward Cunningham (disclosure: Socialtext Advisor) noted while sitting in the Honolulu airport and thinking of what to call his invention back in 1995. Wikis are deceptively simple, yet extremely flexible. Just as weblogs make the web writable, wikis make the web editable. Since anyone can "Edit this Page" without knowing HTML, it reduces the barriers to contribution while letting users create their own information architecture.

Wikis are constantly in motion and reflect the current shared understanding of the group. At scale you would think this form of collaborative editing couldn't possibly work, but it is comparable in terms of quantity and quality to traditional editorial workflow. Even when put to the difficult task of having strangers agree on definitions. Giving editing rights to everyone means you have to give up some control and identity as an author, but this actually fosters trust, particularly within organizations.

They are also cool because they are the antithesis of traditional enterprise software with its top-down design the imposes process, ontology and structure upon users. By giving users the power to create, link and form groups it serves the domain of business practice, the unstructured collaboration that leverages informal networks. A wiki can serve group activities quickly, so a project can begin with conversation and prototyping instead of waiting for a tool to be created or implemented. Work done in a wiki creates its own usable archive, rather than requiring a side-activity or having designated experts determine what is of value. The bottom-up approach also produces a dense link structure that has its own emergent patterns, with the best content and expertise rising to the top, to inform decisions based on what your organization actually knows.

We are familiar with Wikipedia, the (amazing) jointly-edited encyclopedia built on wiki technology. Are there other interesting public wikis?

The orignal WikiWikiWeb, MeatballWiki for meta-discussion about wikis, collaborative travel guide Wikitravel, SCO vs. IBM for trial coverage and the IA wiki on information architecture. Wikipedia also has some sister project such as Wiktionary, Wikibooks, Wikiquote and Wikisource.