see http://search.cpan.org/~ivorw/CGI-Wiki-Plugin-Diff-0.01/
I have converted the diff code which was OpenGuides specific, into a plugin for CGI::Wiki. I intend to develop this module further (see Pod section TODO), but I am inviting feedback from others, especially those who are hosting CGI::Wiki sites.
The code is a direct rip from OpenGuides::Diff.pm, but I wrote nearly all of this module anyway. Please let me know - reply on-list or off-list, if you would like to see more specific functionality in this module, as I have time to put into it :).
Ivor.