Apache is a free and open-source cross-platform web server software.
jQuery plugin for seeing if the images are loaded.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
Pollyfills for XHR2 and File API
Plupload is JavaScript API for building file uploaders.
WordPress is a free and open-source content management system written in PHP and paired with a MySQL or MariaDB database. Features include a plugin architecture and a template system.
WPMU DEV Smush is a WordPress plugin that allows you to optimise images without losing quality.