The Simple Cloud API brings cloud technologies to PHP and the PHPilosophy to the cloud, starting with common interfaces for three cloud application services:

• File Storage Services
• Document Storage Services
• Simple Queue Services

You can start writing scalable, highly available, and resilient cloud applications that are portable across all major cloud vendors today.

http://simplecloudapi.org

The OpenStack Open Source Cloud Mission: to produce the ubiquitous Open Source Cloud Computing platform that will meet the needs of public and private clouds regardless of size, by being simple to implement and massively scalable.

• Le site: http://www.openstack.org
• Le Blog http://planet.openstack.org
• Le code https://launchpad.net/openstack

OpenStack Compute (nova):

• Read Documentation: http://nova.openstack.org

OpenStack Object Storage (swift):

• Read Documentation: http://swift.openstack.org

http://heroku.com/

http://www.engineyard.com/products/appcloud

• Amazon Elastic Compute Cloud (EC2)
• Amazon Simple Storage Service (S3)

http://www.eucalyptus.com/