Wikis offer a great opportunity for collaboration. Both as self-hosted or as a subscription service, there are many wiki engines to choose from and Wikimatrix makes it easier to compare them side-by-side.
As says this entry from Wikipedia itself:
“A wiki is a page or collection of Web pages designed to enable anyone who accesses it to contribute or modify content, using a simplified markup language. Wikis are often used to create collaborativewebsites and to power community websites. The collaborative encyclopedia Wikipedia is one of the best-known wikis. Wikis are used in business to provide intranets and Knowledge Management systems. Ward Cunningham, developer of the first wiki software, WikiWikiWeb, originally described it as “the simplest online database that could possibly work”.
In the case of a class or workshop being delivered via a wiki platform, the instructor/facilitator has full access to page history information to see who adds/edits content and what exactly was contributed by each individual.
For businesses, wikis, in their essence, offer an intuitive and easy to update knowledge management system and document collaboration tool, harnessing the collective intelligence of many to provide just-in-time, just-enough, just-for-me information.