A rich API Used for programming of single-page Web applications and Web applications synchronicity. Models and Views - The single most important thing that Backbone can help you with is keeping your business logic separate from your user interface. Collections - A Collection helps you deal with a group of related models, handling the loading and saving of new models to the server and providing helper functions for performing aggregations or computations against a list of models. View Rendering - Each View manages the rendering and user interaction within its own DOM element. If you're strict about not allowing views to reach outside of themselves, it helps keep your interface flexible — allowing views to be rendered in isolation in any place where they might be needed. Routing with URLs - In rich web applications, we still want to provide linkable, bookmarkable, and shareable URLs to meaningful locations within an app. Use the Router to update the browser URL whenever the user reaches a new "place" in your app that they might want to bookmark or share. Conversely, the Router detects changes to the URL — say, pressing the "Back" button — and can tell your application exactly where you are now.

* Sparks intention is to provide a pure Java alternative for developers that want to (or are required to), develop their web application in Java. Spark is built around Java 8's lambda philosophy, which makes a typical Spark application a lot less verbose than most application written in other Java web frameworks. * Spark focuses on being as simple and straight-forward as possible, without the need for cumbersome (XML) configuration, to enable very fast web application development in pure Java with minimal effort. It’s a totally different paradigm when compared to the overuse of annotations for accomplishing pretty trivial stuff seen in other web frameworks. * Spark is a simple, lightweight and not opinionated pure Java web framework that doesn't get in your way, unlike in other Java web frameworks, you can structure your application as you want.