As more and more hardware platforms support parallelism, parallel programming is gaining momentum. Applications can only leverage the performance of multi-core processors or graphics processing units if they are able to split a problem into smaller ones that can be solved in parallel. The challenges emerging from the development of parallel applications have led to the development of a great number of tools for debugging, performance analysis and other tasks. The proceedings of the 3rd International Workshop on Parallel Tools for High Performance Computing provide a technical overview in order to help engineers, developers and computer scientists decide which tools are best suited to enhancing their current development processes.

Grid computing systems utilize the heterogeneous networked resources, such as computation, information, database, storage, bandwidth, etc., through the Internet. The systems can operate in predefined and organized ways or form the collected resource systems through self-organizing and decentralized ways. Even with the various types of abundant resources in the Internet, the resources that can be organized and operated in the presence of multiple resource owners with the uncertainty of resource availability and quality are scarce.This volume contains refereed and invited papers presented at the 3rd International Workshop on Grid Economics and Business Models held on 16 May 2006 at the Singapore Management University, in conjunction with GridAsia 2006. It includes contributions by researchers and practitioners from multiple disciplines that discuss the economy of the systems concerned, with focus on the operational and deployment issues of Grid Economy.

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.