Periodically, various APIs in Ember.js may be deprecated. During a minor release, for instance when upgrading from version 1.9 to 1.10, you may see new deprecations fire in your codebase. Until a major revision such as 2.0 lands, code firing such deprecations is still supported by the Ember community. After the next major revision lands, the supporting code may be removed. This style of change management is commonly referred to as Semantic Versioning. * Given a certain model, which of the three controller options should I be using? * Which controller is generated by the framework if I do not specify one? * When using an object controller, why should the this context not be passed to actions if it has the properties of my model? For these reasons, the Road to Ember 2.0 RFC listed object controllers as a concept to be removed from the framework.