Never tested, and I don't think so. A lot of the mambo/joomla compatibility comes from the roots of the 2 systems. Joomla changed their design quite drastically with 1.5 and I don't know what effort would take to make it work for both. When we get through with the next few releases adding large features, it may be something we look into, but we make no assertions that it works now (or will).
What about mambo?
