not at all.. AWS has its own cloud solution like Azure But some other provider uses OpenStack like OVH, citycloud etc

The answer is No, AWS does not use any publicly available cloud solutions.

OpenStack is an open source platform for creating and maintaining a cloud Infrastructure as a Service (IaaS). It is mostly directly for the private cloud market, where companies or individual users who needs complete control on how their infrastructure is provisioned can use the platform to create their own cloud.

AWS being a public cloud provider, uses their own custom solution to do the same, they don't use any code from OpenStack and their code base is closed source.