Mojito is an open source MVC framework for building rich web applications using JavaScript. It allows applications to run on both the server and client-side using a single codebase. Mojits are the basic reusable units that make up an application. Models handle data and business logic, views are templates that generate markup, and controllers coordinate between models and views. Mojito applications can gather data using YQL and present it with YUI components to build full-featured web apps that work across devices using a single codebase.