Tiki is an open source PHP system that combines a wiki with a large number of other features in one install. Its own description is CMS groupware, and it is unusually broad.
Everything in one install
Where most systems keep a small core and add plugins, Tiki ships a wide feature set built in and lets you switch parts on and off. A single install can offer wiki pages, articles, forums, file galleries, trackers, calendars and more without adding anything.
The consequence for anyone moving content out is that a Tiki site can hold several different content types at once, each in its own structure. Establish which features are actually in use before assuming it is a wiki.
Content types you may find
- Wiki pages, with version history
- Articles, closer to blog posts
- Trackers, Tiki’s structured data feature, with no clean equivalent elsewhere
- File galleries, which can store files in the database or on disk
- Forums, if enabled
What moves cleanly
Wiki pages and articles transfer as text without much trouble, though wiki markup usually needs converting. Version history is often lost. Trackers are the hard part: they are effectively custom database tables, and moving them means designing an equivalent by hand.