Alloy is a powerful MVC framework built on Node.js that is integrated with Titanium Studio to make Titanium development easier, faster, and more scalable. Key features of Alloy include separating UI and app logic through MVC, developing apps using XML and JSON, reusable widgets and templates, and built-in support for Backbone.js and Underscore.js. The document provides instructions on getting started with Alloy including installing it, creating a sample tab-based app that makes an XHR request and displays results, and generating controllers and models using the Alloy CLI.