Software design & UML diagrams
Gliffy makes it easy to visualize your software project with UML diagrams. For more information about different types of UML diagrams, along with great examples, see https://www.gliffy.com/examples/uml-diagrams.
To help you create them, when you create a new diagram, you can choose from several Software Design & UML templates.
And, several Software Design shape libraries offer typical UML shapes.