If you want to start a new Geomajas project, you can use the maven archetype which should get you up and going in minutes.
Just use the following maven command, and answer the questions.
mvn archetype:generate -DarchetypeCatalog=http://files.geomajas.org/archetype-catalog.xml
You can then start the skeleton application using
mvn install jetty:run
Next steps, see the “Getting started” documentation.