Neat modeler, not so much a simulator.

I guess it's a simulator in that the bond angles and lengths dynamically rearrange as you add new atoms or yank on existing ones. I'm not sure the results are accurate (compared with density functional theory, Hartree-Fock, etc.), but it looks pretty cool. I assume it's doing some sort of force-based algorithm with an integrator.

I think the OP was making reference to the fact that you can connect atoms without regard for valence.

And you can't double connect.

Click on the bond button before adding an atom. It cycles from 1 to 3.

Thanks!

The results are rather wrong, i.e offensive to the eye (try creating aromatic compounds), but as a GUI prototype, it's pretty neat.

cool, if this was more cross browser compliant i would use it on chemsink.com. the current java solution is slow.