Parallax is a very popular feature for site building. There have been many 'parallax lookalikes' created, with just a couple of fixed positioned background images, but this is the 'real thing'.
It was found at Codepen.io, and there is a license and copyright declaration included in the page head. That declaration has to be included in all pages using this particular parallax setup.
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer nec odio. Praesent libero. Sed cursus ante dapibus diam. Sed nisi. Nulla quis sem at nibh elementum imperdiet. Duis sagittis ipsum. Praesent mauris. Fusce nec tellus sed augue semper porta. Mauris massa. Vestibulum lacinia arcu eget nulla.