HTML/JS/CSS Tetris. Rather straightforward code without dependencies.

Built under time constraints (on a plane) as a practice in getting things done,
and subsequently polished.

A playable copy is located at http://jstimpfle.de/projects/tetris-on-a-plane/

To those asking for a license: Thanks for your interest and your nice stars.
As far as I'm concerned, use of the code is as free as can be (and as can
beer). The credit goes to the original Tetris author. Note also that there is
an abundance of Tetris clones on the web, many of which are probably similar in
implementation, so I'm not interested in adding complicated lawyer words that
nobody understands.