Open Stack

The wikipedia page isn't exactly clear, to me.  I see that it's cloud 
computing, and that rackspace and NASA are involved.  Sounds good!

What is, or is not, openstack?
What are some use cases?


Can it be used for something cpu intensive, to take the load off the local 
machine?  For example, bitcoin mining?  Presumably there would be a cost.

Can I use it with docker, or some similar container, for a web service?

Does my local machine need to be on for such a web service to be 
available?




thanks,

Thufir