Rackspace this morning announced it had acquired ObjectRocket, a Boston-based firm that offers hosted MongoDB as a service. The buy brings the popular NoSQL database into Rackspace’s fold, potentially as a service deployable within its own cloud offerings.

Pat Matthews, senior vice president of corporate development at Rackspace, said, “Databases are the core of any application, and expertise in the most popular database technologies will be critical to us… As we look to expand our open cloud database offering into the MongoDB world, we are really excited to work with the entrepreneurs and engineers at ObjectRocket.”

MongoDB was created by what began as a content-management company called 10gen. The original CMS project was canned in favor of working specifically on MongoDB, which had been developed as a back-end document store for the system.

Today, 10gen and MongoDB are leading the charge of the NoSQL revolution. To that end, MongoDB itself has evolved significantly since its creation and is now one of the most popular schema-less data stores in the NoSQL pack, according to the 451 Group.

One area in which MongoDB has drawn criticism, however, is in the ease of scaling the database. Numerous blogs have been written complaining about the difficulty of expanding a MongoDB to cluster-size; this comes primarily because MongoDB is relentlessly focused on ease of development, rather than on ease of administration. One such blog, Kiip.me (from a mobile application development company), claimed it too was harmed by underlying MongoDB design choices to even attempt scaling it out.

In addressing that, ObjectRocket could provide some significant value for Rackspace, provided the service is able to still automatically scale MongoDB instances.

Chris Lalonde, cofounder and CEO of ObjectRocket, said, “ObjectRocket is thrilled to join the Rackspace family. With Rackspace’s open cloud philosophy and our shared emphasis on providing the highest level of customer support, we feel this union is an ideal fit. Since the beginning, our focus has been on creating a DBaaS (Database-as-a-Service) platform that would perform, scale and support critical workloads in a superior manner. Joining forces with Rackspace will enable us to achieve this goal, while delivering one of the most advanced MongoDB DBaaS solutions on the market.”

The NoSQL market as a whole is expected to continue its growth, according to the 451 Group. In a recent report, the group stated that “NoSQL software revenue is expected to grow at a [compound annual growth rate] of 82% to reach US$215 million by 2015.”