skrollr hasn't been under active development since about September 2014 (check out the contributions graphs on https://github.com/Prinzhorn/skrollr/graphs/contributors) and I don't have any plans for doing major changes to it. Please consider this before using skrollr in production as problems with new browser versions, especially on mobile, will most definitely surface. To be honest, mobile support always sucked (because mobile browsers are hard) and you shouldn't compromise UX for some fancy UI effects. Ever.
Actually, skrollr is much more than "just" parallax scrolling. It's a full-fledged scrolling animation library. In fact, you can use it and still have no parallax scrolling at all. But I wanted to sound hip and use some buzz-words. By the way, skrollr leverages HTML5 and CSS3 ;-)
Moved to the wiki.
First of all: look at the examples and read the source ;-). This might give you a feeling of how stuff works and you can see how some patterns can be implemented.
skrollr allows you to animate any CSS property of any element depending on the horizontal scrollbar position. All you need to do is define key frames for each element at certain points in top scroll offset.
With skrollr, you put the definition of your key frames right where they belong (to the element) using a syntax you already know (plain CSS).
If you would rather have the keyframes inside a separate file, take a look at skrollr-stylesheets.
First of all you want to include the
skrollr.min.jsfile at the bottom of your document (right before the closing