For those that don't know it yet, there has been a split between Miro, the original creators of the Mambo content management system and the Mambo developers. It seems that disagreements regarding how Mambo was controlled led to the split, and the developers have created a new project called Joomla!. This will leave many wondering which project to follow: Mambo or Joomla!
Being a developer, I guess I'll side with the developers, but will play it by ear to see what happens next. For more information, check out opensourcematters.org and this article.