99 LINES? That's huge. How about this one in 227 characters?
http://xem.github.io/sheet/
:)
Back when it appeared on HN, the first thing I entered was =(function(){for(;;){}})() — which predictably froze the browser.
Trying to find a sufficiently-robust way around this restriction ended up shaping the Web Worker based structure. So, thanks for the inspiration & golfing!