Vide – Easy to use video background jQuery plugin.
CoverVid – A jQuery HTML5 background video cover.
Wallpaper – A jQuery plugin for smooth-scaling image video backgrounds. jQuery plugin for smooth-scaling, element-filling backgrounds.
Blurr – jQuery plugin to create nice blur backgrounds for images.
jQuery Video Background – A jQuery plugin to play full screen videos in the background of a web page.
Blur.js – jQuery plugin that produces psuedo-transparent blurred elements over other elements.
Supersized – A jQuery plugin for full screen background slideshow. This jQuery plugin has features to autoplay, fit to landscape, fit portrait, random slides, pause options, slideshow speed controls, thumbnail navigations and more.
Backstretch – A simple jQuery plugin for dynamically resizing the images to fit the background of any page or element. Also, allows you to add a dynamically-resized, slideshow-capable background image to any page or element.
Adaptive Backgrounds – A jQuery plugin to extract the dominant colors from an image and apply it to its parent background. This is a great replacement of using the img tag nested with a parent element.