http://moi3d.com/1.0/docs/moi_introduction.htm
Running commands

You accomplish different tasks in MoI by running commands.

Some commands may apply their work immediately and then exit, while other commands may go through different stages waiting for you to pick points, select additional objects, or adjust various options before they are finished. Sometimes you may need to click the Done button to signal that you are finished with a stage. You can also right-click inside of a viewport, or push the Enter key as shortcuts for clicking Done.