How does it snow on Google, by typing Let it snow [closed]

Question

I know Google is actually promoting CSS3 and HTML5. I have seen that "

do a barrell roll

" will rotate the page. but I am not sure how it snows when you type

Let it snow

is this a CSS3 trick or a javascript?

EDIT UPDATE:

I tried this trick by disabling javascript and it did work STILL, so it is not a javascript

Answer 1

By inspect its code with Chrome's Developer Tool, I think it's done with HTML5 Canvas Element.
And here is my clone of the frost effect: http://wong2.github.com/SnowClone
get my code at: https://github.com/wong2/SnowClone