HTML5 is, in simple terms, a new language for the web that among other things will allow for videos and animations to play without the need for Flash. It can also breathe new life into old video game art styles.
Joe Huckaby over on the Effect Games blog has a great piece up showing a few examples. Taking the work of artist Mark Ferrari and applying an old 2D technique known as "colour cycling", we're left with some beautiful backgrounds that show what's possible from games running on platforms like the internet or mobile phones when HTML5 becomes more widely-adopted.
Mark Ferrari was a background artist on a lot of classic Lucasarts adventure games for the PC, like Monkey Island and Loom, so there are few better people to use to showcase the technique. The examples here are mere still images; to see them running in all their windy, rainy glory, hit the link below.
Old School Color Cycling with HTML5 [Effect Games, thanks Rich!]