The camel:dot goal of the Camel Maven Plugin is used to generate Visualisation diagrams for your Enterprise Integration Patterns.
The plugin will then try and convert the DOT file into a HTML, PNG and SVG representation. To do this an installation of GraphViz is required to be on your PATH.
So to use this plugin, please download Graphviz then put it on your PATH.
By default the plugin will evaluate the dot executable, but you can overload this by configuring the plugin's executable property. e.g.
A good example application to get you started is the Spring Example.
Your generated PNG/SVG files will then be in the target/site/cameldoc directory - assuming Maven could find your DOT executable.
Note that you do not need to explicitly run this goal; you could just integrate this plugin into the normal Maven report generation.
In Camel 1.4 you can disable the execution of DOT by setting the useDot configuration parameter to false.