Ember.js is an open-source JavaScript web framework, based on the Model–view–viewmodel (MVVM) pattern. It allows developers to create scalable single-page web applications. Developed by emberjs
License: Open Source
Derby is a lightweight framework focused on real-time web applications, offering flexibility and ease of use, while Ember.js is a more opinionated framework with strong conventions, making it better suited for larger applications with robust community support.