Wiki software is a kind of collaborative software that runs a wiki system. This usually allows web pages to be created and edited using a common web browser. It is generally implemented as a software engine that runs on one or more web servers, with the content stored in a file system, and content changes kept in a relational database management system.
In addition to the Wiki engine itself that employs the wiki technology, Wiki software could include all of the software required to run a wiki, which might contain a web server such as Apache. In some cases, like in ProjectForum, or in some WikiServers, the web server and wiki engine are bundled together as one self-contained system that can often make them easier to install.