Mediawiki

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, simple to use and install.

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.