Just what is a cloud, anyway?

The dominant theme at last week's OSCON conference was cloud computing. So what can I say about cloud computing?

As I see it, "cloud computing" is a step towards a the commoditization of computing power. The cloud model moves server hardware and base software out of corporate data centers and into provider data centers. Clients (mostly corporations) can use cloud computing services "on demand", paying more as they use more and less as they use less.

Cloud computing services fill the second tier, between the front-end browser and the legacy back-end processing systems. This is where web processing is today.

The big players have signed on to this new model. Microsoft has its "Azure" offering, Amazon.com has EC2 and S3, and Google has its App Engine.

Cloud providers are similar to the early electric companies. They build and operate the generators and transmission lines, and insist on meters and bills.

Moving into the cloud requires change. Your applications must be ready to work in the cloud. They have to talk to the cloud APIs and be designed to run in multiple instances. Indeed, one of the features of the cloud is that new instances of your application can come on-line as you request more computing power.

Like the early electricity companies, each provider has its own API. Apps for the Amazon.com platform cannot be (easily) transferred to Google. And Microsoft not only has its own API but uses the .NET platform with its development languages. I suspect that common APIs will emerge, but only after time and possibly with government assistance. (Just as the government set standards for control pedals in automobiles.)

I suspect that apps on the cloud will be different from today's apps. Mainframes had their standards apps: accounting and finance, mainly. When minicomputers arrived, people ported the accounting apps to minis with some success but also created new applications such as word processing. Later, PCs arrived and absorbed the word processing market but also saw new apps such as spreadsheets. Networked PCs created e-mail but left the old apps in stand-alone mode. The web saw new applications like LiveJournal and Facebook. (OK, yes, I know that e-mail existed prior to networked PCs. But networked PCs made e-mail possible for most people. It was the killer app for networks.)

Each new platform sees new applications. Maybe the new platform is created to serve the new apps; maybe the new apps are created as a response to the new environment. I don't know the direction of causality, but I'm leaning towards the former. With cloud computing, expect to see new applications, things that don't work on PCs or on the currrent web. The apps will meet new needs and have advantages (and risks) beyond today's apps.