Apache JSPWiki is a leading open source WikiWiki engine, feature-rich and built around standard JEE components (Java, servlets, JSP).
Some of its features include:
You can see who is using JSPWiki today, and the WikiMatrix page shows you a comparison with other wiki's.
JSPWiki is open-source software that is released under the Apache Public License. This website (https://jspwiki-wiki.apache.org) serves as the platform for project collaboration. The JSPWiki community welcomes any help with the project. You don't need to be a software developer to get involved -- there are many other ways to contribute. See the Getting Involved page for more details.