PlantUML in a nutshell

PlantUML is a component that allows to quickly write :

Diagrams are defined using a simple and intuitive language. ( see PlantUML Language Reference Guide ).

This can be used within many other tools.

Images can be generated in PNG, in SVG or LaTeX format. It is also possible to generate ASCII art diagrams (only for sequence diagrams).

(You can edit the text if you want,
the diagram will be dynamically updated!)
describes the following diagram :

This example is working thanks to the online demo server.