Η Full Screen Mario developed it Super Mario Bros (remember his game Nintendo from the 80s) to HTML 5. This practically means that Mario, Luigi and the whole gang is coming in your web browser.
The site was created by Josh Goldberg and allows users currently play the initial levels of the game using the arrow keys or create their own maps using a program processing levels, as mentioned in the Mashable.
This version uses the same music and the same animation as the old video game, but it only works with Chrome.