The Controller is a time tracking software application that started as a personal project in 2011 and has since been adopted by multiple companies for tracking time spent on tasks. It uses Ruby on Rails on the server side and jQuery, Backbone.js, and SCSS on the client side, with MySQL for data storage. The software includes a rich mobile version based on Spine.js and has over 1000 commits from 10 contributors, with unit tests and 90% code coverage.