ember-engines
Composable Ember applications for ambitious user experiences
...On a technical level, engines and applications are remarkably similar: they each have their own container, registry, context, and namespace. However, unlike an application, an engine does not boot itself nor does it control its own router. Engines rely on their hosts to fulfill these responsibilities. The often-used example of this is a "blogging" application. While a blog itself could be a full-fledged application, you may also wish to use it as a specific subsection of your overall application.