Amazon Web Services has officially released its Elastic Compute Cloud (EC2) hosted computing service.

The company said today that the service would no longer be considered a beta product and would be supported by a service level agreement. The SLA will serve as a commitment from Amazon to keep the service up at a rate of at least 99.95 per cent or allow customers to claim a refund on purchased service credits for the system.

EC2 allows businesses to run traditional server deployments on a hosted 'cloud' system. Customers pay for the service on a sliding scale according to the amount of server resources used.

In addition to the SLA, the company has unveiled the first public beta of its EC2 Windows Server and Microsoft SQL Server services. Both offerings allow users to run deployments of the Microsoft server systems within the EC2 cloud computing platform.

"When we launched Amazon EC2 over two years ago, the idea of accessing computing power over the web was still a novel idea," said EC2 general manager Peter De Santis.

"We've listened closely to our customers for the past two years and worked backward from their requirements, adding important new features such as those we are announcing today."

The addition of SQL and Windows Server support was first announced by the company in early October. However, what should have been big news for Amazon was quickly overshadowed by Microsoft when chief executive Steve Ballmer revealed that the company was working on a cloud computing system of its own.