shine.js is a nice and useful JavaScript library for creating shadows and shine effects to elements. You can install it via bower or direct download, add the script, change the light direction. and more. Among its features you have:

– Dynamic light positions
– Customizable shadows
– No library dependencies, AMD compatible
– Uses text or box shadows based on content
– Works in browsers that support textShadow or boxShadow and auto-prefixes if necessary

It was designed by Naim Sheriff and coded by Benjamin Bojko. It is free to download, improve and use.