DokuWiki
DokuWiki is a simple to use Wiki aimed at the documentation needs of a small company. It works on plain text files and thus needs no database. It has a simple but powerful syntax which makes sure the datafiles remain readable outside the Wiki. Have a look at the complete feature list.
To learn more just visit the DokuWiki Website.
Download
Please refer to download.dokuwiki.org for the download.
Support
Please do not contact me for help and support! In most cases I will not answer. Use the mailinglist or forum instead. This ensures the answer you get will help others, too. It also lowers the number of mails I get.