UML Designer

UML Designer provides a set of common diagrams to work with UML 2.5 models.
ARIS Express

ARIS Express is based on the proven ARIS methodology and industry standards.
Modelio

Modelio is an open source modeling tool supporting natively UML, BPMN and model exchange with XMI.
Diagramo

Diagramo is an online flowchart software
– diagrams (create, edit and share).