"The Open Cloud Computing Interface (OCCI) is an open protocol for all cloud computing services. A RESTful interface, it deviates from the underlying HyperText Transfer Protocol (HTTP) only where absolutely necessary and can be described as a "Resource Oriented Architecture (ROA)".RWS Unlike other envelope-based protocols which operate in-band, all existing HTTP features are available for caching, proxying, gatewaying and other advanced functionality such as partial GETs.

Each resource is identified by URL(s) and has one or more representations which may include a hypertext (e.g. XHTML5) rendering for direct end-user accessibility. As such OCCI can present both a machine interface (using native resource renderings) and a user interface (using HTML markup with forms and other web technologies such as Javascript/Ajax). HTTP content negotiation is used to select between alternative representations and metadata including associations between resources is exposed via HTTP headers (e.g. the Link: and Category: headers).

In this way OCCI is not responsible for the representations themselves, rather it enables users to organise and group resources together to build arbitrarily complex systems of inter-related resources. It relies on existing standards for rendering and does not make any recommendations of one standard format over any other."

Note that all user contributed content falls under the OGF IPR Policy.