Left Mb:zoom in area, Ctrl+Left Mb:zoom out area, Right Mb:move, Wheel:fine zoom in/out.
Left Mb click:switch between the Mandelbrot set and the corresponding Julia sets.
You can mirror the image by using area zoom from reverse directions.
This is only a HTML5 canvas demonstration. For a full featured Mandelbrot / Julia set generator download MandelX.
I noticed on my legacy system (Athlon XP 2200+) that Mandel4 preset is surprisingly slow. Knowing both architecture (K7, K10) fairly well I thought this magnitude of speed difference in single threaded mode is not reasonable. Considering the relatively small amount of data big speed differences can be attributed to either smaller and slower caches (and certainly not the absence of integrated memory controller) or the lack of SSE2 support in the K7 core. So I decided to make an experiment with the help of my program Phenom II Tweaker. I had disabled the SSE2 feature flag on my Phenom II and repeated the tests. Bingo. The cause of the dramatic slowdown seems to be the missing SSE2 support. Here are the results:
I have included Firefox 8.01 result for comparison (last version of Firefox with acceptable legacy code performance). Multi-threaded numbers are missing since they are irrelevant.