OpenStack is a free and open source cloud computing platform. It’s mainly used to build IAAS (infrastructure as a service) solution.
VMware vSphere platform can be used with the OpenStack framework and this video shows how you can integrate it using the vSphere OpenStack Virtual Appliance (VOVA).
To be said, the vSphere OpenStack Virtual Appliance has been created for educational purposes as a proof of concept. It’s not an official product and it doesn’t come with any support. VMware also discourage its use.