It does work in my tests, though the sliders were screwy, not at all as shown in the image. That might be OS or version related. I'm not sure what purpose this tool serves, except as a demo of a mandelbrot set. In the context of student interest, this fails my definition of good documentation by a long shot. It essentially contains no documentation. The only help it has is in the website description. The author should have included this in the function help. The uicontrols completely lack tooltipstrings - they would have been nice to provide, rather than having the user guess what they do given the lack of other help. Pretty picture though. While some might argue that I should vote for deletion, I'll just say it needs serious improvement in its help and documentation. Raising my rating would take only a few lines of help that explain what the user is looking at and what the controls mean.