The DeltaCloud API provides a single API interface to work with multiple cloud computing providers.
The DeltaCloud Core provides a RESTful API, and backward compatibility across different versions of support cloud platforms.
Deltacloud API supports the following providers:
DeltaCloud is open-source and downloadable by anyone.
Currently there is no available DeltaCloud API as a service. Anyone can download and deploy, but there is no Softare as a Service (SaaS) version.
I smell an opportunity for someone to offer as a service, and provide an on-demand universal cloud computing web API.