In theory, the public cloud is the ideal answer for leveraging extra computing resources when local and private cloud infrastructure aren't enough. But deploying internal software in the public cloud is much easier said than done. Ravello Systems, however, thinks it has a solution in the form of a hypervisor for your hypervisor. The concept may sound loopy, but it actually represents what could become a crucial new way of taking advantage of virtualization and the cloud.

When it comes to understanding virtualization, Ravello Systems has respectable credentials. The company was founded in 2011 by the same team that created Qumranet, which produced the KVM virtualization hypervisor that is now embedded into the Linux kernel. Red Hat (NYSE: RHT) acquired Qumranet in 2008.

Fast forward five years, and the Ravello team is now focusing on solutions for helping organizations to "spill over" their internal operations into the public cloud. As Navin Thadani, one of the Ravello founders, explained in an interview, "Enterprises today have realized the benefits of the public cloud," but they want to use it in conjunction with their internal data centers. And that can be challenging, since applications developed to work on internal infrastructures aren't always readily adaptable to cloud environments, where the operating systems, networking parameters and other factors involved are often very different from those of in-house systems.

To allow enterprises to overcome that barrier, Ravello has debuted a new product designed for developers who want to test on-premise applications in the public cloud. The tool, which became available Feb. 5, 2013, in public beta form, works on a software-as-a-service (SaaS) model and is based on what Ravello calls a "cloud application hypervisor" named HVX.

In contrast to other hypervisors, such as KVM or VMware (NYSE: VMW), HVX is "designed from the ground up to be run and optimized on a virtual environment," according to Thadani. "It runs nested inside another VM," and as a result makes it possible--in conjunction with an an I/O overlay and application framework that Ravello has also developed as part of the product package--to abstract applications from the cloud environment in a way that will allow them to work as if they were running on an enterprise's internal infrastructure.

There are some limitations. For one, Ravello remains focused for now on marketing to software developers who want to use the public cloud for testing their on-premise applications. The company has yet to pursue the wide swath of other potential use cases for bridging internal infrastructure and the public cloud, although such efforts will likely come down the road. Meanwhile, the Ravello platform currently supports only the public cloud services from Rackspace (NYSE: RAX), Amazon (NASDAQ: AMZN) and HP (NYSE: HPQ)--a lineup that should satisfy the vast majority of enterprises, but which doesn't represent the full range of cloud platforms available. Thadani promised that that will change as well, however, as Ravello evolves.

The restrictions on the beta product notwithstanding, Ravello is doing an interesting thing at the crossroads of traditional and cloud computing. It is making it possible to fuse the public cloud, with its scalability and cost-effectiveness, and on-premise operations with a seamlessness that has been previously unknown. For now, the scope of the Ravello offering remains small, and it will likely take enterprises some time to develop procedures for capitalizing on the value it offers. But this is a significant innovation that could have major implications not only for how organizations use the public cloud, but for the very meaning of hypervisor itself--which now, in the Ravello conceptualization, has more to do with bridging disparate environments than with virtualization narrowly defined.