Tangle is a JavaScript library for creating reactive documents.
If you like explanations like these, maybe you'll like the live explanation of the Burrows-Wheeler Transform that I wrote a few years back: <a href="http://canonical.org/~kragen/sw/bwt.html" rel="nofollow">http://canonical.org/~kragen/sw/bwt.html</a><p>I keep meaning to put it on the back of a better library so that it doesn't hang up the page if you type a too-long string.