Wikka 1.1.6.5 is a maintenance release that introduces no new functionality, but addresses several minor issues including PHP5 compatibility.
Announcement http://blog.wikkawiki.org/2008/06/25/announcing-the-release-of-wikka-1165/
Downloads: http://docs.wikkawiki.org/WhatsNew
Changelog: http://docs.wikkawiki.org/WikkaReleaseNotes