Are UML diagrams only for Object oriented approach?

Question

Is there any restriction that UML diagrams could be drawn only for systems with Object oriented approach? Can we use them for other approaches (E.g.: procedural)?

Answer 1

UML say "all is class", see MOF on OMG page. Some UML diagram have non-objets origins (like a use case diagram or activity diagram), but now is the notation based on object/classifier concept. OOP and "system of classifiers" is not the same... You can use UML for all models based on classifier and object concepts (se SysML, UML profile).