The ability to easily build an update center that users of your application can use to update their software, is a very useful feature of the NetBeans Platform. And being able to build this from the command line means that it can be useful on a build server.
For an Ant-based application, you can call the nbms target in the build script of the suite. The nbms and update.xml file will be built to <suite folder>/build/updates. This can also be executed from the NetBeans IDE by right-clicking on the suite project > Package As > NBMs.
With a Maven-based project, you can use the following command in the parent project folder:
The nbms and update.xml file will be placed in the parent project folder, under target/netbeans_site.