Azure Stack is a technology stack that customers can run in their own datacenters. It's meant to encourage businesses who can't, or won't, move to the public cloud to still get some of the cloud's technological and operational cloud-computing benefits if not the cost-savings.
Microsoft Partner Director of Program Management Ryan O'Hara, explained, "Azure Stack is an extension of Azure. The experiences are the same as in Azure, the application programming interfaces are the same, so artifacts, like Azure Resource Manager, are portable across (the two)." This, in turn, means you can use Azure Stack as a hybrid cloud with Microsoft's public Azure cloud.
Application developers can maximize their productivity using a 'write once, deploy to Azure or Azure Stack' approach. Using APIs that are identical to Microsoft Azure, they can create applications based on open source or .NET technology that can easily run on-premises or in the public cloud.
IT professionals can transform on-premises datacenter resources into Azure IaaS/PaaS services while maintaining oversight using the same management and automation tools that Microsoft uses to operate Azure.
Organizations can embrace hybrid cloud computing on their terms by helping them address business and technical considerations like regulation, data sovereignty, customization and latency.
As time goes on, Microsoft will add to these features with new technical previews. "Microsoft will add services and content such as OS images and Azure Resource Manager templates to help customers start taking advantage of Azure Stack. Also, Azure has 100s of such applications and components on GitHub and as the corresponding services come to Azure Stack, users can take advantage of those as well. In this context, we are already seeing early excitement from partners - especially open source partners - like Canonical, who are contributing validated Ubuntu Linux images that enable open source applications to work well in Azure Stack environments."
So, it's no surprise that "Ubuntu will form an integral part of the Azure Stack offering, given 70 percent of the most popular cloud workloads run on Ubuntu. Users of Azure Stack will run the same software that runs on the Azure public cloud."