Nice rundown on the private cloud market by Derrick Harris over at GigaOm. (Specifically, IaaS infrastructure—although categorization can still be a little tricky at the margins. For example, there are a variety of complementary IaaS management products that are beyond the scope of this discussion) The money quote:
OpenStack is what happened to the private cloud market and forced so many acquisitions, pivots and even one closure. Users, investors and everyone, really, were waiting for some promise of cloud interoperability and portability (aka something other than Amazon, VMware or Microsoft) and OpenStack delivered it. Further, for the service provider community — which has arguably bolstered the sales of private cloud software since its inception — OpenStack provided a relatively engineering-free path to public cloud offerings (compared with building their own from scratch, that is) without fear of being at the mercy of a startup that might fold tomorrow and take its core technology with it.
It's striking how quickly this market has evolved. Some of the companies discussed in the article—the names were all drawn from a June 2010 GigaOm report—never attained much of a profile. But, from that 2010 vantage point, others that looked as if they were in a good position to be important players appear to have faded.
The OpenStack story is an ongoing one, especially with respect to commercially-supported products based on the OpenStack project. But we can say that OpenStack already offers a great example of how open source combined with a robust community around that open source has great power.
I mention the community (including the companies involved through the OpenStack Foundation—including my employer, Red Hat) as well as the code because it's the two together that have helped OpenStack gain such ground. OpenStack had a strong start in July 2010 based on contributions from Rackspace and NASA. But I'd argue that it was the creation of the OpenStack Foundation and the putting in place of an appropriate governance structure that really allowed the project to become the focal point for broad industry collaboration.