C3.js vs Epoch by Fastly: What are the differences?

C3.js: A D3-based reusable chart library. c3 is a D3-based reusable chart library that enables deeper integration of charts into web applications; Epoch by Fastly: A general purpose real-time charting library for building beautiful, smooth, and high performance visualizations. Epoch is a general purpose charting library for application developers and visualization designers. It focuses on two different aspects of visualization programming: basic charts for creating historical reports, and real-time charts for displaying frequently updating timeseries data.

C3.js and Epoch by Fastly belong to "Charting Libraries" category of the tech stack.

Some of the features offered by C3.js are:

• Comfortable - C3 makes it easy to generate D3-based charts by wrapping the code required to construct the entire chart. We don't need to write D3 code any more.
• Customizable - C3 gives some classes to each element when generating, so you can define a custom style by the class and it's possible to extend the structure directly by D3.
• Controllable - C3 provides a variety of APIs and callbacks to access the state of the chart. By using them, you can update the chart even if after it's rendered.

On the other hand, Epoch by Fastly provides the following key features:

• Built for Developers - open source
• Real-time Charting
• Unified Styling

C3.js and Epoch by Fastly are both open source tools. It seems that C3.js with 8.42K GitHub stars and 1.4K forks on GitHub has more adoption than Epoch by Fastly with 4.99K GitHub stars and 292 GitHub forks.