Multiculturalism and Integration

abstractions and concepts that let applications access and share resources and services across dis-tributed, wide area networks, while providing com-mon security semantics, distributed resource management performance, coordinated fail-over, problem determination services, or other QoS met-rics that are of importance in a particular context. For some time, such problems have been of cen-tral concern to developers of distributed systems for large-scale scientific research. Work within this community has led to the development of Grid tech-nologies,1 which have been widely adopted in sci-entific and technical computing.2 Grid technologies and infrastructures support the sharing and coor-dinated use of diverse resources in dynamic, dis-tributed virtual organizations3—that is, the creation, from geographically distributed compo-nents operated by distinct organizations with dif-fering policies, of virtual computing systems that are sufficiently integrated to deliver the desired QoS. In particular, the open source Globus Toolkit described in the “OGSA and the Globus ToolKit” sidebar has emerged as a de facto standard for con-struction of Grid systems. Projects building on the Globus Toolkit range from scientific collaborations concerned with remote access to specialized exper-imental facilities—for example, the Network fo