I would like to talk about this Drupal Module, Chaos Tool Suite (ctools). This suite is primarily a set of APIs and tools to improve the developer experience. It also contains a module called the Page Manager its job is to manage pages. In particular it manages panel pages, but as it grows it will be able to manage far more than just Panels. It includes the following tools.
The first is the Plugins tools, to make it easy for modules to let other modules implement plugins from an INC file. Remember an INC file is a text file that contains declarations, headers, functions, or other data referenced by a program’s source code. Second tool I want to talk to AJAX responder, tools to make it easier for the server to handle AJAX requests and tell the client what to do with them, check the link below for more information on the tool of the Chaos Tool Suite (ctools) module for the Drupal Content Management System.
Please note as of now Chaos Tool Suite (ctools) is for Drupal 8 / 9 / 10.