| The last decade has noted a substantial change in the ways global industries, businesses, and home users apply computing devices, including a wide variety of ubiquitous computing resources and advanced Web services. Initially, the focus was on localized computing resources and respective services; however, the capabilities have changed over time and we are now in an environment consisting of sophisticated, virtualized, and widely distributed Business On Demand utility services. Major global organizations, solutions providers, service providers, and technology innovators, whom we have already discussed in the earlier chapters (and even those we have not yet discussed), have absolutely contributed to this technology evolution. In the previous chapter, we explored several grid architecture points, and the architectural relationships between grid and other distributed computing technologies. As we can see from this discussion and the following illustration, the evolution of Grid Computing is progressing at a very rapid rate. This computing evolution is tightly aligned with the incredible and very rapid evolution of the Internet and other open standards architectures. As shown in Figure 4.1, the evolution of Grid Computing is broadly classified into three generations. This Grid Computing evolution is discussed in detail by Roure, Baker, Jennings, and Shadbolt. Figure 4.1. The Grid Computing technology road map is simply illustrated in terms of generations.  In previous chapters, we explored some of the major projects and organizational initiatives that contributed to the first generation and second generation of Grid Computing. The first two phases were concentrating on large-scale resource discovery, utilization, and sharing within the virtual organizational boundaries. The major drawback in these two phases was the lack of transparency among the middleware, which contributed to monolithic and noninteroperable solutions for each grid environment. This difference in the first two stages results in a vertical tower of solutions and applications for resource sharing among organizations. Today, we are in the third generation of Grid Computing where the applications and solutions are focusing on open technology-based, service-oriented, and horizontally-oriented solutions that are aligned with the other global industry efforts. The grid infrastructures are clearly transitioning from information aware to that of knowledge-centric frameworks. In this chapter we begin to explore a detailed discussion on the third generation of technologies, and the respective grid architectures and the road map that is guiding the next generation of grid technology initiatives. The next generations of Grid Computing technologies that are channeling this third generation of grid initiatives are noted as: | 