Since Flux is a pattern, developers have been able to create various implementations of Flux to better fit their needs. Here, Brian creates his own implementation for Flux by creating instances for the Flux actors instead of using singletons.
Are you new to React? In this article Jack does a great job of breaking down the fundamental building blocks of React from components, to props, state, and everything in between. If you're just getting started with React, this is should be one of the first posts you read.