Boris RenskiHistorically, commercial software provided enterprises with reliability and scalability, especially for mission-critical tasks. No one wanted to risk failure in finance, operations, or any essential or enterprise-wide areas. So, enterprises considered open-source technology only for less important, more tactical purposes.

Recently, however, many large IT organizations have developed significant open-source strategies. Cisco, Dell, NASA and Rackspace came together to give birth to OpenStack. VMware acquired SpringSource and shortly thereafter announced Cloud Foundry, its open-source PaaS. Amazon, and others built solutions entirely on an open-source stack. Whole categories of technologies, such as NoSQL databases, made their way to mass adoption shortly after being open-sourced by Google and Facebook. There has been more activity in open source during the last two years than in the preceding decade. So what’s going on here?

Without a doubt, cloud is the IT topic that’s been grabbing headlines and investment dollars in the past few years. The recent high level of activity in open source noticeably correlates with the cloud movement, because there is a deep, synergetic relationship between the two. In fact, cloud is the primary driver for the increased adoption of open source.

In general, open-source projects typically require two components to get community uptake. First, the nature of the project itself has to be technologically challenging. Successful open-source projects are largely about solving a set of complex technological tasks vs. just writing a lot of code to support complex business processes, such as the case with building enterprise software. Linux, MySQL and BitTorrent are all good examples here.

Second, it requires a high rate of end-user adoption. The more people and organizations that start using the open-source technology at hand, the more mature the community and the technology itself becomes.

Cloud has created an enormous amount of technologically challenging fodder for the open-source community. The adoption of cloud translates to greater scale at the application infrastructure layer. Consequently, all cloud vendors, from infrastructure to application, are forced to innovate and build proprietary application infrastructure solutions aimed at tackling scale-driven complexity. Facebook’s Cassandra and Google’s Google File System/Hadoop/BigTable stack are prime examples of this innovation.

However, it is important to note that neither Facebook nor Google are in the business of selling middleware. Both make money on advertising. Their middleware stack may be a competitive advantage, but it is by no means the competitive advantage. Because companies want to keep IT investments as low as possible, a the natural way to drive down costs associated with scale-driven complexity is to have the open developer community help address at least some of the issues to support and growing the stack.

The result? Instances like Facebook’s open-sourcing of Cassandra, and Rackspace contributing its object storage code to OpenStack. Ultimately, cloud drives complexity while cloud vendors channel that complexity down to the open developer community.

What about end-user adoption? Historically, enterprises were slow to adopt open source. Decades of lobbying by vendors of proprietary software have drilled the idea of commercial software superiority deep into the bureaucracy of enterprise IT. Until recently, the biggest selling point for commercial enterprise software was reliability and scalability for mission-critical tasks; open source was OK for less important, more tactical purposes. Today, after leading cloud vendors like Amazon, Rackspace and Google built solutions on top of an open-source stack, the case against open source for mission-critical operations or supporting the required scale is no longer valid.

But the wave of open-source adoption is not just about the credibility boost it received in recent years. It is largely about the consumption model. Cloud essentially refers to the new paradigm for delivery of IT services. It is an economic model that revolves around “pay for what you get, when you get it.” Surprisingly, it took enterprises a very long time to accept this approach, but last year was pivotal in showing that it is tracking and is the way of the future.

Open source historically has been monetized by leveraging a model that is much closer to “cloud” than that of commercial software. In the case of commercial software, you buy the license and pay for implementation up front. If you are lucky to implement, you continue to pay for a subscription that is sold in various forms: support, service assurance, etc. With open source, you are free to implement first, and if it works, you may (or may not) buy commercial support, which is also frequently sold as a subscription to a particular SLA.

The cloud hype has helped initiate the shift in the standard for the IT services consumption model. As enterprises wrap their minds around cloud, they shy further away from the traditional commercial software model and move closer to the open-source/services-focused model.

It is also important to note that the consumption model issue is not simply a matter of perception. There are concrete, tactical drivers behind it. As the world embraces the services model, it is becoming increasingly dominated by service-level agreements. People are no longer interested in licensing software products that are just a means to an end. Today, they look for meaningful guarantees where vendors (external providers or internal IT) assure a promised end result.

This shift away from end-user licensing agreements (and toward SLAs) is important. If you are a cloud vendor such as, you are in the business of selling SLA-backed subscription services to your customer. If, at the same time, you rely on a third-party vendor for a component of your stack, the SLA of your vendor has to provide the same or better guarantees that you pass on to your client. If your vendor doesn’t offer an SLA or only offers an end-user license agreement, you end up having to bridge the gap. These gaps that an organization is forced to bridge ultimately affect its enterprise value. As we move away from the EULA-driven economy and more toward SLAs, open source stands to benefit.

Ultimately, as cloud continues to mature, we will continue to see more and faster growth in open source. While the largest impact so far has been in the infrastructure space, open-source popularity will eventually start spreading up the stack toward the application layer.

Boris Renski is cofounder of Mirantis, a Silicon Valley-based software engineering company that delivers custom cloud platforms.