Building

You can continue to use Maven to build artifacts after you use the Eclipse editor to make changes. Expand the parent cas3 project and right click on the pom.xml. Select Run as ...
You can directly invoke one of the Maven goals in the list, except for two things. First, these preconfigured goals are broken as of the initial release of Helios (Eclipse 3.6) but in addition, it is tedious to have to navigate to the pom.xml file in the cas3 project every time you want to do a build. So instead choose the Run Configurations ... at the bottom.
Select the Maven Build template on the left, then give the job a name like "cas3build", use Browse Workspace to select the cas3 project, choose an appropriate goal, and decide if you want to run the tests with every build. Save the result and run it.

Once you have configured a named Maven build configuration, it will be available in the Run pulldown from the menu bar
This provides a quick and convenient way to rerun the build every time you make a change. You can follow this model for every Maven project you want to run interactively from within Eclipse.