Will my modules written for Mambo and Joomla! work interchangeably?
As the minor and major revision numbers progress for both Mambo and the Joomla fork, the codebases will begin to diverge. In fact, reports state that some third-party modules written for Mambo 4.5.3h are not compatible with Joomla 1.0.7. The problem is not widespread at the moment, but it may worsen…or may not.