Four days before Microsoft launches its Azure cloud platform to developers at a conference in L.A., Amazon has come up with a .Net software development kit to help Windows developers produce code that runs in Amazon's EC2. It's probably just coincidence. But let's see what they're getting with AWS SDK for .Net.Late Wednesday the Amazon Web Services unit posted the availability of AWS SDK for .Net on its Web site. The SDK "makes it even easier for Windows developers to build .Net applications that tap into the cost-effective, scalable and reliable AWS cloud," it said. I wasn't aware that Amazon had made the EC2 environment especially easy for Windows developers in the past. If anything, I would have assumed that it left those developers to their own devices, particularly during the two-year beta phase of EC2 when you could only run Linux virtual machines in the Amazon Web Services cloud. I would concede that Amazon did add Windows as a choice for your virtual machine a year ago, and that made things easier for Windows developers, if they were targeting EC2.

Now Amazon is offering C# code samples, Visual Studio project templates, an AWS .Net library and documentation, all of which will help Windows developers "get started in minutes with a single downloadable package." The .Net library will make it simpler to use the Amazon APIs that invoke the Web services for EC2, S3 storage and Amazon SimpleDB database services. More information on the SDK's components can be found at this site.

What's most impressive to me, however, is how the cloud, which sometimes seems to fit into three distinct categories (Infrastructure as a Service, Platform as a Service and Software as a Service), will see its edges blur, its shape shift and its services begin to cross over between categories. If Amazon is going to make it easier to develop Windows code for the EC2 cloud, it can easily offer the same tooling in the cloud and allow the development to occur in the environment in which it will be deployed, which has its own advantages.

Until now, Amazon has looked exclusively like infrastructure as a service. Azure, as Microsoft talked about it, looked like platform as a service, with lots of rich Windows tooling. Now Amazon would like to be viewed as infrastructure, but perhaps with many platform attributes for a variety of developers. It's begun to build out a resource site for Windows developers, including popular community libraries, developer information articles and code samples. It's done the same for Java, PHP and Ruby developers as well.

The distinctions between infrastructure as a service and platform as a service are important in helping define our thinking about the cloud, but I would urge everyone not to take them too seriously. It will only be a short while before the distinctions will blur, if not disappear entirely.