The source code of each of the software components is available on their respective sites. For statistics on the source code (and other useful information), please see : Black Duck Open Hub. If you want to use WikiSuite (versus auditing and/or contributing to the source code), please see: How to install WikiSuite
WikiSuite's policy is to work closely with each upstream project to add / improve features there. See also: "Upstream First"
Some quick links to the various repositories: