Backbone's core is small, well-tested, and nicely maintained. However, developers may need additional functionalities to be used by a complex web application. The power of the Backbone framework depends on modularity and flexibility. Existing components can easily be either extended or replaced; thus, many developers create their own plugins.
There are over 100 plugins that can be downloaded and used in your application from https://github.com/documentcloud/backbone/wiki/Extensions,-Plugins,-Resources. In this book, we are going to use some of them, so we need to know how to extend our application with plugins.
If the plugin is a single JavaScript file, simply copy it into the lib folder of the project and include it in index.html.
<script src="lib/backbone.plugin.js"></script>
Alternatively, if the plugin has been shipped with additional files, such as CSS and images, place all the plugin files in the plugin-name directory under the lib folder, and then include the JS and CSS files in index.html.
The Creating a Backbone.js extension with Grunt recipe in Chapter 8, Special Techniques