Using this definition enables us to discuss a variety of technologies, regardless of the specific business model. It avoids, for instance, the need to discuss the merits of so-called "open core" models that feature a community-based central core software component that's distributed freely, surrounded by extras and add-ons that can be purchased or subscribed to at an additional cost from the vendor.
With this definition in hand, it becomes clear that there are three main reasons why open source is so central to the success of cloud computing.
* Legitimacy. One of the very first, and perhaps more obvious reasons for the presence of open source in cloud computing is the fact that it is so highly pervasive already within the mindset of IT.
Even two years ago, a four-year survey conducted by cloud vendor Zenoss showed that open source was a significant presence in 98% of enterprise companies. It is highly unlikely that this number has dropped in the ensuing two years, which means open source is a part of essentially every enterprise operation out there today.
This legitimacy of open source is not something that was enjoyed during, say, the turn of the century when fear, uncertainty and doubt was heaped with scorn on new technologies like Linux and MySQL by proprietary competitors. It was not until mega-companies like IBM started seriously looking at Linux and investing in its development that enterprises started taking a closer look what was once viewed as a cancer by esteemed observers like Microsoft.
Today, that problem is non-existent. Very few people doubt the power and flexibility of open source technology, and now open source tools are considered among the first options by any IT procurement staff, not the last.
Cloaked with this newfound legitimacy, open source cloud computing tools are very much accepted in today's IT shops.
* Chuff. As any new paradigm such as cloud computing evolves, there is always going to be chuff in the early days. As various vendors look around and see a new sector opening in front of them, there is that rush to jump in and be an entrant within that new frontier.
Cloud computing has a particular name for this phenomenon: cloudwashing. This is when every vendor under the sun will try to apply "cloud" to whatever technology they have, in the hopes of catching someone's eye with a shiny new wrapper around a technology that might not be the best fit.