What Wiki has...

What Wiki flavor (open/free) has these features built in or with a stable add-on:

-Article versioning and aging/expiration
-WYSIWYG editor (FCKeditor on mWiki works well)
-Authentication to lock away areas from those who shouldn't see (i.e. IT docs for backend maintenance that the rest of the org doesn't need)
-Runs well on Firefox on a Mac
-LDAP v3 or OD/AD authentication

This is a mostly Mac environment (church) so SharePoint's requirement for IE for most functionality is out.

It doesn't have to be a wiki either. Another PHP/MySQL based solution would be welcome too.
Any suggestions?