I don't think there's much in it; I think I like the icosahedron due its very large amount of symmetry but cube and octahedron would be my second choices.

Is Flash bad for that sort of thing? Isn't that where it's useful?

Well, you know, proprietary closed platform, better to support open standards, yadda yadda. Also Flash applets always seem to eat a bigger proportion of my CPU than they should reasonably need to. OTOH, I can't deny that my Flash applets respond very smoothly and look very slick for minimal coding effort – especially compared to the Java ones on the MathWorld page, which have a low refresh rate and no antialiasing. (Flash gave me antialiasing for free, just by using its graphics APIs in the perfectly obvious way.)

Probably one of these days I should look into whatever all this newfangled stuff is that's supposed to be the open-standards alternative to Flash. Embedded SVG manipulated by Javascript, or something like that, isn't it?

"Embedded SVG manipulated by Javascript, or something like that, isn't it?"

Yup, <canvas> is the magic tag. Although as you say in practice Flash gives great results and can be created with free tools.

Depends what you mean by great results - for me the flash player segfaulted twice while trying to view these, and even when working it caused firefox to freeze for 30 seconds while opening.

Oh yeah, fair enough. I'd like a good free alternative if one arrives, but it still seems to work better than the alternatives for this sort of thing at the moment.