Amazon's Elastic Compute Cloud (EC2) hosted infrastructure service for developers will expand its choice of operating systems and databases to include Microsoft's Windows Server and SQL Server.

Amazon is now privately beta testing the additon of Windows Server and SQL Server to EC2 but plans to roll out the options to all developers before the end of the year.

The addition of these options has been requested by many developers and is in line with Amazon's stated goal of supporting "any and all" programming platforms, OSes and databases in EC2, according to Amazon.

"You will be able to use Amazon EC2 to host highly scalable ASP.NET sites, high performance computing (HPC) clusters, media transcoders, SQL Server, and more. You can run Visual Studio (or another development environment) on your desktop and run the finished code in the Amazon cloud," Amazon wrote in an official blog post announcement on Wednesday.

In comments to the blog posting, several developers welcomed the news. "The sun is going to shine a little bit brighter tomorrow. This is fantastic news and big props to the AWS team and Microsoft for making this happen, wow," wrote one identified as Richard Waldvogel.

EC2 is part of Amazon's AWS suite of cloud-computing infrastructure services for developers. With EC2, developers can host and run their applications on Amazon servers, increasing or reducing capacity as needs change. Amazon doesn't require developers to enter into long-term contracts or agree to minimum spending in order to use AWS services. The services are billed on a pay-as-you-go usage basis.

Amazon Web Services aims to offer developers a suite of generic computing, payment, billing, fulfillment and Web search services so that they can focus on the work of making their applications.

Amazon Web Services is part of the growing cloud-computing trend, in which IT vendors are hosting software in their own data centers and making it accessible via the Internet so that the clients don't have to install it on their premises. This model, in theory, reduces hardware provisioning costs for clients and saves them the time and effort of installing and maintaining software.

Other providers of cloud computing services and software include Google and Salesforce.com, although most major enteprise software vendors are also embracing this model and offering some of their applications on a hosted basis.

Among the biggest drawbacks of the cloud-computing model is the concern about the security of hosting critical consumer data in a third-party's data center. Another issue is the loss of control by IT departments over the performance and availability of the hosted software and services, which the vendor is now responsible for.