Do you know of any free websites for viewing 3 dimensional complex molecules/compounds?

Question

or any software that would allow you to create/play with different molecules three dimensionally by adding or subtracting groups etc., particularly heterocyclics.

the more technical the better ie. showing or calculating charge, angles, steric hidrance etc.

Answer 1

Go to chemstore.com and download the free 30 day trial version of Chemoffice. They sell a reasonably priced student version too. Chemdraw will allow you to draw anything, Chem3D will allow you to visualize the structures in 3D.