Salesforce.com may have made the early headlines, but it has since been joined by a plethora of software-as-a-services companies selling almost any service that can be hosted in a data centre.

The model has had some unlikely heroes, such as Amazon.com, which has championed the platform-as-a-service model with its Elastic Compute Cloud (EC2) and Simple Storage Service (S3). Google also offers a range of cloud services, including its Google Docs applications.

According to Google's head of enterprise for Southeast Asia, Richard Suhr, this year will represent a tipping point in cloud computing adoption in Australia and around the world.

He says companies most commonly come to Google initially because they are having problems with their mail, either in storing it or dealing with spam.

"Once we've talked through the benefits of Gmail, the conversation invariably turns to the rest of the Google Apps suite, and the collaboration products like Google Docs and Spreadsheets," Suhr says. "That's where many companies really get excited — because that's a whole way of working that wasn't available to them before. Sharing calendars with ease, working together on the same document from remote locations. . . it's exciting stuff."

Almost every other large IT company has also weighed in with a cloud computing model of their own.

Microsoft has tried to redefine the model by calling it software plus services, eschewing the idea of running everything in the cloud in favour of a hybrid model that also makes room for the client/server model on which it has built its business.

"We don't want to impose on the customer the delivery model," says Gianpaolo Carraro, leader of Microsoft's platform and development group in Australia. "The delivery model is really something the customer has to decide in terms of the amount of control they want to keep, versus the cost element of it."

Microsoft also hosts SharePoint and CRM software online for those companies that want those services, and also has its online Live consumer services, including the storage service SkyDrive and Webmail service Hotmail.

The next stage in its cloud campaign is Azure, a version of Windows designed to work in the cloud, which provides a platform for software developers to create cloud applications that sit on Microsoft's technology stack. This includes both a cloud version of the operating system, as well as many of the services that run above it. Commercial availability of Azure is expected in the next 12 months. -- B Howarth