Free or Fee Wiki Tools
To wiki requires wiki style software running on a local networked computer of your own or a hosted service. Long lists of wiki hosting services or wikiware applications themselves are readily available. Just as there are web server and blog servers providing free file storage and Internet sharing services, there are also wiki servers providing free hosting services. Users have taken to calling these wiki farms. Some wiki farms are free and some charge. There are many pages with lists of wiki farms: Wikipedia/wiki farms; Google Directory; Yahoo Directory. However, searches for comparisons, reviews or evaluations of wiki farm services have yet to be successful.
Others have focused on the software applications that run wiki services and have made comparison tables of wikiware options (splitbrain; wikipedia). Choices and features change frequently, so doing your own research is essential to having current information. Narrowing these choices from the over 100 available wiki applications can be helped by referring to top ten lists. Even the top ten lists have trouble staying current. One of the most recent developments in the wiki universe is the concept of an enterprise wiki, a set of intranet documents that anyone in the organization can edit or annotate, such as provided by Socialtext and Jotspot which function like wikis but add additional structure.
Free services include free hosting services and free wiki server software, in contrast to paying a fee for more features or buying wiki server software.
Still open to debate is the early leadership in wiki hosting. Just as there are variations in blog software depending on the hosting service, so is the case with wiki servers. The features you want will determine the choice of wiki farm. One of those critical features is RSS service for notification of wiki page changes. This includes: Socialtext; Kwiki; Purple Wiki; and JSP Wiki.
For a quick experimentation with the wiki way, follow this link get your first wiki page posted at http://riters.com/?content=Make%20A%20Wiki.