The TWiki, a WikiWikiClone written in perl, and documented at http://TWiki.org has some nice features that have been added about a year ago in their structured text markup language. Their text formatting rules can be found at http://TWiki.org/cgi-bin/view/TWiki/TWikiDocumentation#TWiki_Text_Formatting .
Some conformance between the two formatting rules would aid in people moving from using a TWiki? into using a ZWiki. I am personally considered the move because of the large number of additional capabilities that exit within the Zope community as an application server platform.
The TWiki? is an application that runs underneath Apache or some other web server and supplies the pages which are created dynamically by the application of variables and mark up substutions within the page. Zope offers much more capability, especially when mixing content types.
Anyway my two cents. Ricky West