Annotation It is tempting to think of virtualisation as simply a vehicle for server consolidation. However, this is like thinking of an automobile simply as a replacement for the horse-drawn buggy. While the analogy may be appropriate, it oversimplifies what actually happened that allowed an automobile to be built, thus failing to provide the reader with a true understanding of the magnitude of change that took place. To provide a true understanding of how the automobile replaced the buggy, the underlying technologies that were involved need to be identified: mass production with repeatable processes, internal combustion engines using advances in metallurgy to create lightweight alloys, lubrication, electrical and tire technologies, petroleum refining and distribution, and so forth. The convergence of these technologies around the automobile led to an economic transformation that changed the world in the first part of the twentieth century. The Business Value of Virtual Service Oriented Grids describes the authors' insights about how the convergence of three well known technologies are defining a new information technology model that will fundamentally change the way we do business. It is not because wonderful new applications will reach the market. That_s only the beginning. These technologies allow the development of applications in a federated fashion using service modules that we call servicelets. The difference is that these federated or composite applications can be built in a fraction of the time it takes to develop traditional, single-vendor applications. This new environment lowers the bar for application development, opening opportunities for thousands of smaller players worldwide. These three technologies are well known: virtualisation, SOA, and grid computing. The fundamental dynamic taking place is that it will become increasingly easier to plan and schedule corporate data from the applications that manipulate the data from the compute engines on which the applications run. In other words, each of these three entities_data, applications, and processing_can be allocated and metered precisely to support any business goal.