MMB file extension is associated with MultiMedia Builder, a multimedia authoring software developed by MediaChance. MultiMedia Builder allows users to create various multimedia front-ends for their CD /DVDs in an effective and intuitive manner. Users can create presentations, menus, autorun settings, or media apps.

MMB files store information accessed by MultiMedia Builder for internal processing. MMB files should not be opened or edited manually. MMB format is now considered obsolete.