Unfortunately contact has been lost with Marc Rohlfing who created roWiki. Originally information on roWiki was published on http://www.rowlff.de/rowiki/ but that website has vanished and his former email address no longer works. However, his system can apparently be downloaded from http://maintained.by.noone.org/rowiki/.
The open source spirit of roWiki is maintained in qwkzit, which is available under the same Licence terms.
An internet search will reveal other "daughter" systems based on Marc's original.