If you're a developer using the Microsoft platform and want to learn Windows Azure development, Developing Applications for the Cloud on the Microsoft Windows Azure Platform (Patterns & Practices) is the book for you. It's a clear book which rides on a good practical case that covers most of the important angles. Because this is a Practice & Patterns book, it also spends quite some time teaching you the right mindset for building (multi-tenant) cloud applications.

The downside of the book is that it really assumes a good familiarity with the Microsoft .NET Framework and C#. Without that, you're not going to understand much of the cases, apart from the high-level cloud information. That said, the book starts with a good explanation of why you would want to build cloud applications, the types of scenario's that fit well, and what Windows Azure (and in more general terms Platform-as-a-Service) development means. The example case really covers most scenario's and choices people will come across, and that means it also covers all the core technologies within Windows Azure. Another great thing about the book is the many links to articles and other (free e-)books that provide deeper insight into a certain aspect or technology. Be aware that Windows Azure is a fast moving platform, with changes on a regular basis. Although most of the core concepts in this book will remain the same for a long time, it can't keep up with all the new developments. I hope new editions will follow to keep up with the changes.

In the early stages I've commented on Microsoft not going the right way, because a major selling point could be that you can run Azure in the cloud or in your own data center. That seemed not to be possible. When Azure almost went live, MS had changed sufficiently to maybe make this possible in the future. With Azure Appliance, this is now definitly a reality.

Earlier this year I was pretty negative about the Azure story from Microsoft. My main gripe was that (from my perspective at the time) it was not a write-once, run-anywhere story, so you couldn't run your current apps in Azure without modification. I'm very pleased about what I've seen now from PDC. Microsoft has opened up Azure in many ways, giving you much more control over what's happening. In fact, you can get your own virtual machines and have complete remote admin access. Also, they've been really thinking about how to tie your existing hosting environment to Azure and vice versa. It will be possible to connect a web app inside Azure securely to a database server in your own data center.

I must say I'm impressed at how well Microsoft has listened to all the feedback about Azure. With all the changes they've implemented I feel that it has now become interesting for some of the services my company is implementing, whereas previously we weren't even considering Azure.

I read this post from Steven Martin at Microsoft and frankly I'm disappointed. Microsoft is not the only company building cloud computing services, but they have a clear advantage over most of the providers: they own the operating system. As such, a unique selling point would definitly be that they can provide you with cloud services, but also enable you to run your applications in your own data center without modifications. If I build an application for the Windows platform, I want to build it once and be able to run in on any server infrastructure. As it looks now, this is not possible. Once built for the cloud, it must remain in the cloud unless you refactor the application for use in your own environment. I really hope Microsoft sees that this is a mistake and that it will actually gain them clients if they allow this. There is another factor here and that's trust. I'd like to have a backup scenario in case Microsoft fails to deliver. With the Azure platform as is, there is no backup scenario. You either go for it full-blown, or you don't. It is my belief that many people will decide not to go with Azure in the first place because of this. In fact, I am now much more reluctant to tell my clients about Azure as an option.