Diagramo - Diagramo is an online flowchart software - diagrams (create, edit and share)
UML Designer - UML Designer provides a set of common diagrams to work with UML 2.5 models.
BOUML - BOUML : An UML toolbox running under Linux, MacOS X and Windows to specify and generate code in C++, Java, Php, Python, Idl and MySQL
Yakindu Statechart Tools - Discover YAKINDU Statechart Tools – a free statechart tool for the specification and development based on the concept of state machines.
StarUML - StarUML
IBM Rational Rose Enterprise - IBM Rational Rose Enterprise is a functional unified modeling language software based on object-orientation.