Insert and edit UML diagrams into your documents with the DotUML add-In.
The available diagrams are : 
 - Use Case
 - Sequence
 - Class
 - State
 - Deployment
 - Graphviz
Diagrams are generated from a simple and easy-to-learn pseudo-code. This allows quick creation of diagrams and easy modifications. For example, adding a message in a sequence diagram is done with a simple line of code:
sys1 -> sys2 "message label";
For more information and detailed documentation of the language, please visit http://dotuml.com.