Some few weeks ago, the "Simple Cloud API" has been announced. The company behind this is Zend technologies, which calls itself "The PHP Company". More important is the fact that Microsoft and IBM are amongst the supporters of Simple Cloud API. That means that there is a significant momentum behind that approach from the very beginning.
One could argue that this is just another standard or API besides so many approaches we've seen recently. However, the Simple Cloud API is somewhat unique for some reasons:
- It is focused on PHP. You may like PHP or not but it is an important language for web development.
- It is currently focused on the infrastructure layer, with (at the beginning) support for file services, document services, and simple queueing. That might change over time, but it adds to the mainly management-oriented standard approaches which dominate the emerging cloud standards.
- It is usable. It is not a XML-based protocol but really an API which interfaces with existing services. Ready to use from the beginning - look here. However, it is under development so some things might change.
Thus the Simple Cloud API is not only simple but close to be ready-to-use (close to because it still is under development). But it is definitely worth to have a look at.