While it is technically usually feasible to create new pages, and edit old ones on almost any wiki, it is considered bad form to do this if the edits do not reflect the purpose of the wiki. This is called being off topic. The communities associated with some wikis may react very aggressively to the creation of such pages, and delete them almost as rapidly as they are created. Others are more tolerant, but will nevertheless warn the "intruder" that the edits do not conform to community rules. Sometimes new users to wikis do this, and create a walled garden.
To avoid creating such walled gardens, it is better for a user wanting to create a wiki to either host his/her own, though this may require the use of a server, plus wiki software, and since not everyone has their own server or skills to set up wiki software, a viable alternative is the use of a wiki farm, or community wiki space.
Some of the external links below give clues as to where users can find hosting space for wikis. Users who require large spaces should either host their own, or make suitable arrangements with the providers.
External Links