Jean-Christian Imbeault:
I've only found one other wiki that purports to support ACLs but it really doesn't look nor seem to be as good (in other respects) to MediaWiki.
Have you looked at MoinMoin? http://moinmoin.wikiwikiweb.de/ http://moin.sourceforge.net/
It supports ACL's and AFAIK it's a very reasonable wiki engine.