What can you cram into 1K bytes? If you think the answer is "not a lot, then you need to take a look at this year's entries.
You do get a little help - there is a basic runtime environment which includes a canvas element. You can also use audio and video but not WebGL. The program has to run in Firefox, Chrome and Opera - not IE and Opera because they are OS specific.
What is the point of it all?
Well, if you have to ask there is no way you are going to get it, but there is a simple pleasure in achieving a lot with a little. It also forces programmers to be creative in miniature and it is difficult to see how some of the artistic masterpieces would have come about without a limitation on resources.
Take, for example, "You Are Here" by Oakley Jurgens - a rotating globe with the browser's location marked:
Would such a creation have been as sparse without the 1K limit?
Of course there are also lots of impressive random artworks such as Oldskool Plasma by Juhani Imberg:
or Flower of Life by Tristan Brehaut:
There are also lots of favorites such as Life, Pac Man, analog clock, fractal trees and so on. There are also a few games, which is surprising in only 1K. My favorite is Tree Ninja by Lars, which might not be strategic but is still addictive:
However, for sheer amazing impressive ability to pack features into 1K, it is difficult not to mention 1K Meteors by Oscar Toledo G. The animation is smooth, the shooting is fun and it is difficult to win!
There are lots more demos at the JS1K site and you can read the code to find out how it all works.
If you find one that you think deserves to win then post a comment here.
Tetris In 140 Bytes