Here at Zivtech, we are obsessed with creating immersive experiences for mobile and the web using cutting-edge design and Open Source Software like Drupal and Angular.js. One of the web design techniques that we've had on our radar is Parallax Scrolling, which gives depth to a page by scrolling two dimensions of the site at different rates (for example, text in the front would scroll faster than the image behind it). Parallax Scrolling is most often associated with 2D video game development, but has been becoming more and more prevalent on the web (for some live examples see Creative Bloq's post "46 Great Examples of Parallax Scrolling").
Deferring the parallax effect to CSS removes all these issues and allows the browser to leverage hardware acceleration resulting in almost all the heavy lifting being handled directly by the compositor.
This technique, which removes the bulk of the work off the browser, creates the illusion of 3D without bogging pages down. Now, with CSS, we can maintain the same effect without creating a disjointed experience across multiple platforms. Check out Keith's post on pure CSS parallax scrolling websites for code snippets and samples.