How to make Ruby or Python web sites to use multiple cores?

This my Answer to the stackoverflow question: How to make Ruby or Python web sites to use multiple cores?:

I'm not totally sure which problem you want so solve, but if you deploy your python/django application via an apache prefork MPM using mod_python apache will start several worker processes for handling different requests.

If one request needs so much resources, that you want to use multiple cores have a look at pyprocessing. But I don't think that would be wise.