Slim is a PHP micro framework that helps you quickly write simple yet powerful web applications and APIs.
You can find the Slim 3 documentation here.
The chapters you will find here are a description of a Slim 3 fork that has been developed by Enovision GmbH and authored by Johan van de Merwe.
It is using all the specifications of the Slim 3 framework with added functionality. This fork is an easy way of getting your application up and running.