Epoch is a versatile real-time charting library ideal for developers and visualization designers aiming to create smooth, high-performance visualizations using simple APIs. Built on D3.js, it focuses on both basic historical charts and real-time charts that display frequently updating time series data. The tutorial demonstrates the integration of Epoch with PubNub's cross-language SDKs to build a real-time chart, using a Python script as the data source that generates random integers and publishes them to a PubNub channel. On the client side, the tutorial outlines how to set up the necessary environment and create a time-series line chart using Epoch and jQuery, subscribing to the PubNub channel to push real-time data updates to the chart. The process highlights the simplicity of creating real-time visualizations with Epoch, suitable for applications in analytics, IoT, and monitoring.