backbone

Backbone is a JavaScript library that gives web applications a structured way to organize their code. Without something like Backbone, JavaScript-heavy web pages can quickly become a tangle of code with no clear separation between data, logic, and display. Backbone solves this by introducing a few core building blocks: Models (objects that hold your data and fire events when that data changes), Collections (groups of models with built-in sorting and filtering helpers), and Views (pieces of the page that listen to events and re-draw themselves when needed). These pieces communicate with a server through a standard RESTful JSON interface, meaning the app can load and save data to a backend using the same conventions most web APIs already follow.

You would use Backbone when building a single-page web application — where the browser handles most of the navigation and interaction without reloading the whole page — and you want a lightweight, flexible structure without committing to a large, opinionated framework. It is written in JavaScript and is one of the earlier and most influential JavaScript MVC (Model-View-Controller) libraries, though it has been largely superseded by newer frameworks in current projects. Documentation, downloads, and tests are hosted at backbonejs.org.