PBworks.

PBworks, is the world’s largest business wiki host. It was founded in June of 2005 and has over 500,000 wikis and many millions of pages of user-created content. Wikis are a product of the new generation of online collaborative software which allow users to easily create, public or private, “electronic blackboards” where users can quickly add, delete, or change text, pictures, or applications, and also share files with a community of users. PBworks is the leading hosted collaboration solution for business and Education.