As the original authors of the framework say, the ScaleCube is defined as follows:
"An open source project that is focused on streamlining the reactive programming of Microservices reactive systems that scale (http://scalecube.io)."
The central goal of the project is to build highly scalable low latency, distributed systems.
For interaction between services, the toolkit uses Project Reactor 3 and is generally transport agnostic. However, as this book is being written, the default transport is RSocket-Java.
Along with this, ScaleCube offers integration with Spring Framework and provides an annotation based API in order to build scalable, low latency, distributed systems. We will not go into the details of the frameworks' integration here. However, to learn more, please see the following link: https://github.com/scalecube/scalecube-spring.