Simply copy the contents of the github repository and point your HTTP daemon to index.html. Everything should run fine!
There is a demo of CSStris in action here.
This program is to demonstrate an implementation of tetris in the browser. It is a small project I made to get my feet wet in online game development. Sprites were created using aesprite. All code and images are licensed underGPLv2, a copy of which is included as LICENSE.