WiKiss

Easy to use, lightweight, standards-compliant wiki engine with a simple syntax allowing reading the data outside the wiki. All data is stored in plain text files, therefore no database is required.

Wiki software package that powers Wikipedia and all other Wikimedia projects, serving hundreds of millions of users each month.

Organize and store information. Stores documentation in a book like fashion.

Wiki program that stores pages and uploaded files in a git repository, which can then be modified using the VCS command line tools or the wiki's web interface.

Complete markdown-powered wiki contained in a single PHP file.

Wiki-based system for collaborative creation and maintenance of websites.