Buckminster offers functionality and/or integrations pertaining to many activities that are useful to reach in scripted situations, for example invoking 'build'. Such activities are frequently necessary to run in situations where a user is not available, or even in situations where it's not possible to use a graphical user interface. Thus, Buckminster recognizes the need to provide a way to do these things from the command line. This will come in handy in situations such as for automated nightly builds, for example. In Eclipse parlance, this is typically referred to as 'running headless'.
So, to accommodate headless interaction with Buckminster, Buckminster contains a framework to interact with various aspects of it from the command line. This framework is really general purpose, so like many other aspects of Buckminster (and Eclipse in general, of course) it is extension based, thus making it easy to plug in new commands to work seamlessly together with existing. In fact, if you wish to make a headless application and populate it with your own commands only, you can do that.
For more detail, see the following acrticles: