It's a Marionette Behavior for data binding.

1. Download Backbone Stickit;
2. Download the binding.js file;
3. If you are using Boiler, put the binding.js file inside the application/behaviors folder. Create the behaviors folder if it not exists.

Put this in your Marionette ItemView:

behaviors: [{
	behaviorClass: require('behaviors/binding'), // if using webpack|browserify
	bindAttr: 'name', // default attribute for automatic binding
	bindings: {} // custom bindings
}]

Follow the Backbone Stickit Bindings reference.