Microsoft Linux? Completely normal, say the Redmond marketing people. In the VM Depot [1], which is part of the Microsoft Open Technologies site, administrators will now find a huge selection of ready-made Linux virtual machines that can be run in Microsoft's cloud. Most images are based on known distributions, notably Ubuntu, Debian, CentOS, and openSUSE (Figure 1).

Figure 1: With five ratings and three comments, the Debian virtual machine is one of just a few that users have rated.

List of Defects

Anyone who registers at the VM Depot can create and upload their own virtual machines. When this issue went to press, the vast majority of images came courtesy of the BitNami project, which operates an "App Store for Server Software" [2] on its own site. In the store, you will not just find many virtual machines for different applications and cloud platforms, but also popular server software, such as the WordPress blogger tools, all preconfigured.

By default, these virtual machines send various information back to BitNami, including the IP address, the Linux distribution used, and the uptime. If you do not want this to happen, you have to comment out a line [3] in the crontab of the virtual machine.

Caution is advised because each virtual machine in the VM depot can have its own license terms – administrators need to read these texts carefully before using. Registered users can comment on the virtual machines in the depot and rate them with up to five stars, even if they have not yet actually used the VMs.

However, at the time this issue went to press, very few people had used this feature. Only a few machines had more than one review, and comments were only to be found in homeopathic doses. The ratings thus do not provide a decision-making aid (yet). Incidentally, Microsoft does not provide or even certify the virtual machines.

The virtual machines available from the depot can run only in the Windows Azure cloud on Hyper-V. If you have not paid a subscription fee, you can try the service free of charge for 90 days [4]. VM Depot is free to use; the creator of virtual machines can also upload an unlimited number of copies.

Microsoft Recommends Linux

Although Microsoft does not prescribe a particular distribution, it prefers CentOS, openSUSE, SLES, and Ubuntu, according to company statements. The manufacturer has tested these four with Azure and supports them officially. That said, a few limitations apply, which Microsoft summarizes [5]. For example, you must have Ubuntu version 12.04.1 or newer, and this version still requires a special kernel patch. Kindly, the site also provides download links of the distributors. OpenSUSE even offers a complete base image for Azure.

The selected virtual machine can be pushed into the Azure cloud using command-line tools. VM Depot shows you the command required to do so (Figure 2). The command-line tools are available under the Apache License for Linux, as well as Windows and Mac OS X [6]. If you want to upload your own virtual machine, it must be packaged as a VHD image (Virtual Hard Disk format). VirtualBox, for example, can create this format; however, Azure does not yet accept the newer VHDX format yet.

Figure 2: The admin needs to customize the start command shown by the Depot.

Backers

The operator of VM Depot is not Microsoft itself, but the Microsoft Open Technologies (MS Open Tech) subsidiary [7]. Its website claims that it intends to "build a bridge between Microsoft and non-Microsoft technologies." Internally MS calls this "interop." Although the company is only one-and-a-half years old, it already has about 70 staff. Add to this more than 200 employees at the MS Open Tech Hub, which coordinates cooperation between outside contributors and Microsoft employees [8].

MS Open Tech has already contributed code to various open source projects and open standards initiatives, especially where the focus is on connecting with or integrating MS products, as expected [9]. The best examples are the VM depot and Azure command-line tools, for which MS Open Tech is also responsible.

Also, a Mobile Theme for Windows Phone was added to jQuery, as well as support for Windows Store apps. The MongoDB database was improved for cooperation with Azure, and WordPress can now store images and other media in Microsoft's cloud, thanks to a plugin. Also on tap is a .NET library for the Node.js package manager NPM, and the Vi and Emacs editors know the syntax of TypeScript (a Microsoft competitor to JavaScript), thanks to Open MS Tech. Moreover, Apache Hadoop and Microsoft SQL Server can exchange data via a connector.

MS Open Tech has given Eclipse for Java, Hudson, and Jenkins plugin support for Azure and made sure Apache Zookeeper cooperates with Azure. The Microsoft subsidiary released a number of standards developed by Microsoft, including Reactive Extensions (Rx), ActorFx, the Entity Framework (a database mapping tool for .NET), Web PI (Microsoft Web Platform Installer), and the ASP .NET MVC framework.

To find projects that are not tied directly to Microsoft products, you really have to search hard. For example, MS Open Tech worked on the specification for HTTP 2.0 and even published to an Apache server module.