waterpipe.js is a jQuery plugin for smoky backgrounds generation (HTML5 Canvas).
jQuery.BgSwitcher is a jQuery plugin to switch the background image with effects. Here are effect types that can be used: fade,blind,clip,slide,drop,hide (No effect)
Vegas is a jQuery plugin to add beautiful fullscreen backgrounds to your webpages. You can even create amazing Slideshows.
Supersized is a fullscreen background slideshow built using the jQuery library. This jQuery plugin is highly customisable and easy to implement into you website.
Backstretch is a simple jQuery plugin that allows you to add a dynamically-resized background image to any page. It will stretch any image to fit the page, and will automatically resize as the window size changes.
bgStretcher (Background Stretcher) is a jQuery plug-in which allows you to add a large image (or a set of images) to the background of your web page and will proportionally resize the image(s) to fill the entire window area. The plug-in will work as a slideshow if multiple images mode is used (the speed and duration for the slideshow is configurable).