What is backbone.marionette?

Marionette is a JavaScript library that sits on top of Backbone.js and adds the pieces that Backbone leaves out. Backbone gives developers a set of basic building blocks for creating web applications, but it does not include a full application structure. Marionette fills that gap by providing patterns for organizing code, managing views, handling memory, and coordinating parts of the application through events. When building a large web application, a common problem is that the screen gets divided into sections, each section shows different data, and those sections need to update as the user interacts with the page. Marionette addresses this with objects called Regions and Views, which let developers describe what to show where, nest views inside other views, and clean up properly when views are no longer needed. The memory management aspect matters because web applications that create and destroy page sections without cleaning up can accumulate stale objects that slow things down over time. The library is designed to be adopted gradually. You do not have to use every part of it at once, which means you can introduce it into an existing Backbone project without rewriting everything. It works alongside jQuery and Underscore, two libraries that were already common in the Backbone ecosystem. This repository (backbone.marionette) is the older version of the project. The team has moved development to a newer version that drops the Backbone dependency entirely, available at a separate repository. Changes to this repository are now limited to bug fixes. Installation is available through npm or Bower, and full documentation is hosted at marionettejs.com.