The last decade has seen a substantial increase in commodity computer and network performance. Increasingly, computing addresses collaboration, cycle and data sharing and other modes of interaction involving distributed resources. Grid computing is an emerging technology that enables large-scale sharing of widely distributed resources and coordinated problem-solving and collaboration between groups of scientists.Riding on the success of the first two workshops, this year's workshop continues the tradition of providing a useful forum for discussion among researchers, developers and users of grid computing from academia, business and industry. This volume is a collection of the international contributions presented at the workshop, with a focus on grid computing and its applications in science and engineering.