Back in Chapter 4, Introduction to core.async, we had an overview of the main differences between core.async and CES. Another question that might have arisen in this chapter is this: how do we decide which CES framework to use?

The answer is less clear than before and often depends on the specifics of the tool being looked at. We have learned about two such tools so far: Reactive Extensions (encompassing RxJS, RxJava, and RxClojure) and Reagi.

Reactive Extensions (Rx) is a much more mature framework. Its first version for the .NET platform was released in 2011 and the ideas in it have since evolved substantially.

Additionally, ports for other platforms such as RxJava are being heavily used in production by big names such as Netflix.

A drawback of Rx is that if you would like to use it both in the browser and on the server, you have to use two separate frameworks, RxJS and RxJava, respectively. While they do share the same API, they are different codebases, which...