When I started with Drupal 7, I just dove right into site building, customization and theming. I didn’t dissect Drupal into its components. For Drupal 8, I am getting to know all aspects of the framework so I am never distracted by unfamiliar components when building or developing.
CKEditor was a contributed module in previous versions of Drupal but, as one of the most installed modules and the most popular WYSIWYG editor, it has always been one of those contrib modules you install on nearly every site you build. Personally, I have often been annoyed at having to install and configure this one in Drupal 7 so thankfully, it’s now in Core for Drupal 8.
Farbtastic is a widely used jQuery color wheel color picke plug-in that has been around for nearly as long as jQuery itself. In add to it being used in Drupal 8 as a way to change colors in the Bartik core theme. Twitter and WordPress also incorporate it.
This ubiquitous library needs no introduction. It was added to Drupal in version 5. For Drupal 8, one thing to note is that jQuery 2 drops support for versions of IE older than 9.
jQuery UI (https://jqueryui.com/)
Nearly as ubiquitous as jQuery, the latest stable version of this collection of front-end widgets is included in Drupal 8 core.
jQuery Form Plugin (http://malsup.com/jquery/form/)
jQuery Joyride (https://github.com/zurb/joyride)
Created by ZURB, the Joyride jQuery plugin provides an easy way for visitors to create context-sensitive on-page tours. Drupal 8 Core comes with a module called Tour that incorporates the Joyride plugin for easy creation of tours by adding a YAML file to your module's config folder. For an example of its use in Drupal, enable the Tour module, open a View in edit mode and then click on the Tour button that appears on the top right-hand corner. A series of tooltips should appear that guide you through the View workflow.
jQuery Once (http://github.com/robloach/jquery-once)
This jQuery plugin was added for Drupal 7 mostly to reduce boilerplate code. The once() method makes sure that a function is only applied to an element once.
jQuery UI Touch Punch (http://github.com/robloach/jquery-once)
As part of its effort to be mobile friendly, it's important that Drupal 8 be touch compatible but, the version of jQuery UI that ships with Drupal 8 does not support touch devices. The Drupal community decided to include this small hack as a stop gap until touch device support is included in jQuery UI. It allows for the use of jQuery UI widgets such as Draggable, Sortable, Slider and others on touch devices