This thing called Interoperability in another characteristic of the Cloud that must be studied and developed (promoted) with all the attention and care. We must always retain in our thoughts that Interoperability is something very hard to achieve. Our IT history is full of examples: we cannot forget the work needed on simple things like office applications formats and how long we had to wait until we had an open format (ok, now we have two Open Document Formats).

Reuven Cohen on a recent blog post presented very interesting ideas and intentions about this subject. He also had given a name to his efforts: “Unified Cloud Interface”. The UCI specification is, in Reuven Cohen’s intentions, to be implemented as an extension to the Extensible Messaging and Presence Protocol (XMPP). Which is a great decision, reinventing everything every time is usually a very bad decision, and  it also goes against the very definition of Interoperability.

Having a UCI will be major step forward in the matter of Interoperability, but it will only work if we also provide a method to control access and if we base it all in a strong Identity Platform. For authorization we already have OAuth or even a more generic specification like XACML, for Identity management we also have OpenID, and SAML for federated (closed) solutions. Finally we already have the UDDI (Universal Description, Discovery and Integration), which aims to provide an Internet application a way to communicate and interact over the Internet.

In the real world we already have good examples of Interoperability efforts,  besides the ones  in the Identity management field, which I’ve talked about in a previous post,  we have also the work done with OAuth by Google or the one done by Yahoo.