Very cool, but I'm always frustrated by the resolution limit of digital Mandelbrot sets. I'd love to see one that would support (effectively) infinite zooming. Also, I'm aware that it's an artifact introduced by the use of HTML5, but sites that break my back button annoy me.
That would be difficult to implement in javascript, I think. Once you zoom in far enough using a float/double doesn't give you enough precision to calculate each pixel accurately. The typical solution is to switch to some sort of bignum library. That's going to be really slow in javascript.
In general though, infinite zoom mandelbrot programs do exist (don't know of any off the top of my head though), they're just trickier to implement.
Look at the old fractint programming. Like the name implies they used ints [0] for their computation, and this could give you basically infinite zooming, and fast calculation even on a 386. (There's also a linux version called xfractint or so.)
Firefox (4.0) renders this much faster than Safari (5.0.4), Chrome (10.0.648.204) and Opera (11.01) on my MBP (Santa Rosa 2007) with OSX (10.6.7). Could someone else test this too? If reproducible, what could be the reason? Is this simply a Spidermonkey win?
Odd, on my Mac Firefox 4.0 is by far the slowest (the smoothing pass is painful to watch), with Safari (5.0.4) coming in second and Chrome (10.0.648.204) is easily the fastest. MacBook Pro Mid-2009 2.53 GHz Core 2 Duo. Didn't try Opera.
Neat but it seems the pixel plotting could be optimized but I guess I should keep my mouth shut until I've tried to draw that big with my http://plea.se/me/leif/canvas_leif.html