Marionette.js

Marionette.js is a JavaScript framework that provides structure and patterns for building large-scale Backbone.js applications. It extends Backbone with additional views, modules, and architectural patterns to reduce boilerplate and improve code organization. The framework includes specialized view types like CompositeView and CollectionView for rendering collections and nested data structures. Marionette.js provides a robust event system for communication between components and modules. It includes memory management features that automatically clean up views and prevent memory leaks. The framework offers application lifecycle management with regions, layouts, and controllers for organizing complex UIs. While less common in new projects due to modern alternatives like React and Vue, Marionette.js is still maintained and used in legacy enterprise applications built on Backbone.js.