Ember.js Persistence Foundation (epf) is a robust and stable framework for syncing client state with a persistent backend such as a REST API or socket connection. Defining characteristic of epf include:
Correctness is paramount. All other features, including performance, are important, but secondary.
Built around synchronization. Models are never locked and framework semantics assume updates are always coming in from a backend.
Full support for relationships. Related models can be saved concurrently and the framework will automatically order requests around foreign key dependencies.
Robust handling of conflicts and errors.
Forking models is first-class within the framework.
Epf is a functional alternative to ember-data and is used in production at GroupTalent with dozens of inter-related models.