Maybe VRML/X3D. no, seriously, stop rolling your eyes, everyone. ![]()
You could also use a Java applet, or much more easily, a Processing applet. Processing does OpenGL through Java and has an OBJ loader. If you want to, say, put that sculpture in there, you probably want environment mapping to get the reflectivity; OBJ has this, not sure if the Processing loader has it but if not it should be easy to extend.
Incidentally Processing also would be good for mathematically generating forms, 2D or 3D. Actually that's it's primary purpose.
www.processing.org
Flash might be kind of hard for this kind of thing; no real 3D support, so you'd have to either use prerendered sequences or roll your own rudimentary 3D engine from scratch. which is just not really all that fun.