A major challenge in grid computing remains the application software development for this new kind of infrastructure. Grid application programmers have to take into account several complicated aspects: distribution of data and computations, parallel computations on different sites and processors, heterogeneity of the involved computers, load balancing, etc. Grid programmers thus demand novel programming methodologies that abstract over such technical details while preserving the beneficial features of modern grid middleware. For this purpose, the authors introduce Higher-Order Components...