3. What was Dharma's purpose on the Island?

What were they experimenting on? Each of the hatches had their own cameras and purposes, and we know now that the original hatch did have a reason. It was not a sham, although they did make some people believe that it was. What were all these experiments for, and what were they teaching the Dharma? Is the smoke monster a product of the Dharma or of the island? Are there any Dharma members left, either on the island or outside? Why did they fear the hostiles so? What was their overall goal?