Chaos Tools or CTools is one important module in the Drupal framework and a popular one too. It is essentially a suite of APIs and tools that make code readily available for developers and creates libraries for other modules to use. A lot of Drupal modules are in a way or other dependent on it. In this sense, it is lot more helpful to anyone who deals with the customization of sites and works around a number of modules.

Modules that use CTools include Views and Panels. The usage of Chaos Tool can differ for different people and depend immensely on the person using it. There are a number of tools provided by CTools, let’s dive right into them without any further delay and let the chaos begin.

1. Plugins
   Plugins, in simple words, are small chunks of functionality. They are provided as tools that can be added to a Drupal site. There are many different types of plugins available but if their functionality is similar then they belong to the same type.
   
   You can use plugins when you have to implement different iteration of the same task.
    
2. Exportables
   Exportables are a standard way to define “configuration presets”. They can be stored in the database or in the code depending on the choice of the developer and have a built-in export/import functionality.
   
   Exportables support portability of configuration settings and allow configuration to use version control as well as Drush and features integration. It avoids loading data from the database and allows override/revert functionality. 
   
   Exportables can be used whenever it is required for modules to have objects in either the code or the database.
    
3. AJAX Responder
   AJAX responder provided the tools so that the server can handle AJAX requests. It also tells the client as of what is to be done to the coming requests.
   
   This is the part of “core” in Drupal 7 and 8. It is also much simpler than AHAH. AJAX Responder is also SEO compatible. CTools provides multiple AJAX commands to accomplish a variety of simple tasks that can enable you to perform compound actions that allow you to do almost anything.
    
4. Form Tools
   Form tools are provided by Chaos Tool to make it easier for forms to handle AJAX. It, as a result, makes it easy for code on the client side to communicate with the code on the server side.
    
5. Object Caching
   Object Caching is a tool to make it easier to edit an object across multiple page requests and cache the editing work. Although the Ctools object cache is used when storing data during page requests in a multi-step form, Drupal 8 has also introduced TempStore that is very similar to CTools in some ways but owing to the familiarity with the module CTools Object Caching is still preferred.
    
6. Contexts
   Contexts is the notion of wrapping objects in a unified wrapper and providing an API to create and accept these contexts as input. According to this notion, objects involved in page generation have more value than simply creating a piece of output.
    
7. Modal Dialog
   A tool used to simplify the process of putting a form in a modal dialog. It is also used as the standardized way of creating a modal. Modal Dialogs are easy to build themes and are used to handle forms.
    
8. Dependent
   It is a simple form widget that can turn items in a form visible or invisible based on the selection of other items in the form. It is used to make operations (add or remove) in forms much simpler.
    
9. Content
   Content API allows the user to publish the content the on the web in form of API. It provides different pluggable content types and other functionalities which are needed to publish web API. It is a simple and user-friendly solution as you can completely use it to publish a site without having to write a single line of code.
    
10. Form Wizard
    Form Wizard is an API to make multi-step forms much easier. It allows for better organization of UI and also used for better organization of codes. It supports a single point entry, the ability to choose whether or not the user can go forward/ back/ up in the form and easy callbacks to handle the difficult job of dealing with data in between forms.
     
11. CSS Tools
    This is a small tool provided by Chaos Tool for sanitizing CSS so that the CSS code provided by the user can still be brought to use in a safe manner. It provides a method for caching CSS for better performance.

To Sum Up

The CTools (Chaos Tool Suite) is a series of tools for developers and provides them a whole new way of doing things. Even though the module does not offer much value to the end user directly, but adds immense value to the life of a developer by creating a library for other modules to use.

Let me know in the comments below how CTools helped you out of the dig.