Ukiyo.js is a library that generates efficient and dynamic modern parallax effects.
An article about how to create nifty physics-based background scroll effects for your web pages. Matter.js, an excellent open-source JavaScript framework is used to handle the physics.
Brusher is a lightweight javascript library to create interactive backgrounds.
A decorative website background effect where SVG shapes are morphing and transforming on scroll.
The animations are powered by anime.js
A cool moving background effect when hovering an image by using css and javascript.
jQuery Bloodforge Smoke Effect plugin lets you to add a smoke effect background to any HTML element on the page
A simple template that takes advantage of the background-attachment CSS property to create a fixed background effect, with the addition of a navigation to browse through the different sections.
OKVideo is a jQuery plugin that allows for YouTube or Vimeo videos to be used as full-screen backgrounds on webpages. OKVideo aims to be customizable while making some basic decisions about how the plugin should control video. When using OKVideo, all videos will be served from Vimeo or YouTube based on a number of variables like browser, device, bandwidth, etc.
Geometryangle is a jQuery plugin to create fancy geometrical background for websites. Fast frame rate and highly customizable.
A tutorial about creating background effect that can move and zoom when scrolling.
Particles.js is a lightweight javascript library for creating particles.
jQuery Ripples is a plugin to add a layer of water to your HTML elements which will ripple by cursor interaction with WebGL.
You can use this effect to make your static CSS background images more interactive.
Creating dynamic backgrounds transitions on forms with a simple and brilliant idea. Focus on text fields to see this effect.
Particleground is a jQuery plugin for snazzy background particle systems. Particleground includes an optional parallax effect controlled by the mouse on desktop devices and gyroscope on mobile devices.
It works in any browser that supports HTML5 canvas.
Simplax is a simple way to create a parallax background effect with few line javascript in your site.