It's done with CSS:

body { -moz-animation-name: roll; -moz-animation-duration: 4s; -moz-animation-iteration-count: 1; -o-animation-name: roll; -o-animation-duration: 4s; -o-animation-iteration-count: 1; -webkit-animation-name: roll; -webkit-animation-duration: 4s; -webkit-animation-iteration-count: 1; }