OpenStack has been the darling of the cloud scene for four years of unbroken enthusiasm. The term OpenStack is broadly defined, starting with the Enterprise product, through self-made stacks or individual components, and extending to private, public, or hosted clouds.

The project website defines OpenStack as "a set of software tools for building and managing cloud computing platforms for public and private clouds." Tools like OpenStack automate the process of launching and managing virtual machines to meet computing demand. "OpenStack lets users deploy virtual machines and other instances, which handle different tasks for managing a cloud environment on the fly" [1].

The beginnings of OpenStack are familiar to many readers. Hosting service provider Rackspace [2] and NASA [3] both had the idea of developing an open source IaaS platform [4]. The two initiatives were separate until some people involved in the projects had the idea of joining forces. In October 2010, the first version (named Austin [5], for the hometown of Rackspace) saw the light of day.

Since then, two OpenStack editions have been published each year; the name of the next version is always decided at one of the OpenStack summits, and it always has something to do with the venue for the summit – for example, "Kilo" refers to the international prototype kilogram that is kept in Paris.

In the past four years, the OpenStack project has grown enormously. The members and supporters now include major Linux distributors, as well as companies in telecommunications and services [6]-[10]. The current OpenStack release is named Juno, with Kilo expected in a few weeks (Table 1). The number of components has grown from an initial two to the current 11, and the next bunch is already waiting in the wings.

Foundation, Members, and Sponsors

The OpenStack project is backed by a non-profit foundation; since 2012, the OpenStack Foundation [11] has decided the fate of the OpenStack project. Companies and individuals can become members or act as sponsors for the foundation. Several membership categories are available.

From its Gold or Platinum members, the Foundation expects an annual financial contribution. Achieving Gold status is easy; however, Platinum status is limited and is currently fully booked. A Gold member pays 0.025 percent of their annual turnover, but at least $50,000 and a maximum of $200,000. The specifics of rights and obligations for the various membership levels are published at the OpenStack website [12].

On the sponsors page, you'll also see two categories that relate to how well established the company is. Startups – the definition is available on the website – pay less than half the contribution of "mature" IT companies.

Some companies in the OpenStack orbit make their money in consulting and sales around OpenStack. Other vendors, such as cloud providers, use OpenStack as their technical base to provide other services to customers. OpenStack supports both public clouds and enterprise-grade private clouds that operate behind corporate firewalls.

OpenStack Distributors

Several prominent vendors provide their own OpenStack distributions [13] (Table 2). Several criteria could lead one to opt for a specific product. Which OpenStack release and components form the backbone? What hypervisors are supported? What guest operating systems can you use? Which interfaces are available? The devil is in the detail, and you should look closely at the product description before signing. For example, OpenStack supports a wide range of hypervisors [14], including KVM [15], Xen [16], VMware [17], Hyper-V [18], LXC [19], and even Docker [20] [21].

If you don't want to commit to extra expenses or long-term service agreements, you can take your own first steps with community versions. OpenSUSE [22] [23] and Fedora [24] [25] both come with the necessary software to help you get started with OpenStack.

One challenge facing the distributions that support OpenStack is the relatively high update frequency. Every six months a new version appears. Fast adaptation gains you a competitive advantage – but just six months later, the game starts again from scratch.

Service My Cloud, Please

Even an initial look at the list of public cloud providers that offer cloud-based hosting around OpenStack [26] reveals interesting details. Europe, for example, is quite progressive and boasts more than 10 providers. The rest of the world – excluding North America – has just eight. Rackspace [27] is represented on several continents. In Europe, the emphasis is clearly on the western part with a few outliers in Scandinavia.

Table 3 lists the best-known European public providers. Some providers simultaneously serve several countries, which will be of interest to customers who are also geographically distributed. If you shop at Rackspace for your cloud services, you can do so in Europe, the United States, China (Hong Kong), or Australia.

As with the distributions, choosing a cloud provider requires a close look at where the differences lie. For technical or legal reasons, the physical location can be decisive. Additionally, you'll want to consider which OpenStack components are available and which interfaces. Even the version of the corresponding API may be of interest. Of course, price also plays a role.

If a public cloud is too public, but operating OpenStack in your own data center is also not an option, you can always get someone to host a private cloud for you. As you might expect, you will find providers of public cloud services in this domain [28]. You'll find external private providers in both Asia and Europe, but the United States offers the most choices.