Hi!
I have added a new tab by defining the method:
FAMIXTypeGroup>>mooseFinderUMLIn: composite <moosePresentationOrder: 20> composite roassal2 title: 'UML'; titleIcon: MooseIcons mooseSourceText; initializeView: [ RTUMLClassBuilder new ]; painting: [ :view :each | each viewUMLOn: view ]
I do not really like the icon although.
Cheers, Alexandre