Atom.io is expanding its functionality by offering a tutorial on creating a real-time chat plugin using PubNub, which allows developers to engage in pair programming from any location. This tutorial guides users through assembling and implementing a custom Atom package using technologies like CoffeeScript, Less, and SpacePen, with the inclusion of loophole.js to address content security policy issues in Chrome. The tutorial provides step-by-step instructions on downloading, installing, and configuring the package with unique PubNub keys for real-time, uninterrupted collaboration. The process involves setting up Atom preferences and leveraging SpacePen for DOM manipulation, inspired by the slack-chat plugin. The goal is to enable simultaneous code editing and message sharing between users, facilitated by the PubNub real-time service.