Popular module for making 'flyout' menus. 430,000 downloads and 80,000 current installs.

"The proposed HTML "picture" element (see responsiveimages.org, but has not been accepted for HTML 5) is implemented as a display formatter for image fields. This module is a backport of Drupal 8 picture module. This module will deliver alternate image sources based on device capabilities to prevent wasted bandwidth and optimize display for both screen and print. "

This is how to create a plugin for CKEditor. I also show how to integrate it with the WYSIWYG module. It was tested on CKEditor 4.3.4 and the WYSIWYG module version 7.x-2.x-dev from 2014-Mar-20.

Here's how to customize CKEditor in Drupal 7. I recommend using the WYSIWYG module instead of the CKEditor module if you plan on having media module integration. I was not able to get media module working with youtube videos and CKEditor 4+ and apparently that's a known issue (Apr 26 2014).

A nice JS module for drop down and slide out menus

"Panels Breadcrumbs allows you to set your breadcrumbs directly from Panels configuration, and also allows you to take advantage from Panels arguments and contexts as placeholder tokens."

Sets menu links as active for all subpaths of an alias

Here's a couple of quick examples of how to use the image cache API.

"Set JPG quality per image style
This module allows you to specify a custom quality on different image styles you create. After installing and enabling this module, you will have the option to add a new effect to your image styles, enabling you to change the quality."

"Ctools Plugin Stub is a Drush plugin that can help you generate code stub files for ctools plugins."