If you can use a database, mediawiki which runs Wikipedia. If you prefer flat text files, dokuwiki which I personally use at my company and at home. If you al

If you can use a database, mediawiki which runs Wikipedia. If you prefer flat text files, dokuwiki which I personally use at my company and at home. If you already are in the atlassian stack and can't escape no matter what you do, use confluence wiki. But if you don't already have any atlassian products then stay far far away.