Your module won't automatically get built by the Ant script, even if it's in the standard module directory.

To get your module added to the server's list, you'll need to either add it to the core system build (in <LABKEY_ROOT>/server/build.xml, add it to the lists in the "build_classes_parallel" and "build_classes_sequential" targets), or directly invoke the build.xml that was included as part of your module. Either way, you should end up with a helloworld.module in <LABKEY_ROOT>/build/deploy/modules, which will make the server notice it at startup time.

Thanks, Josh