Trying Tikiwiki with MySQL 4.1 now.
Still having problems withs tables (1.9) and drawings (upload work, but don't display).
For Intranet use, TWiki and MoinMoin appear to have a more effective ACL scheme; the ACL is stored in the Wiki itself. Groups can be made with Wiki's as well (and the group list itself can have its own ACL embedded).
So, end-users are totally in control of their stuff. TWiki is a bit slow (CGI), but can run in mod_perl. Both TWiki and MoinMoin support inline maths.
The big plus of MoinMoin is the DesktopEdition