Interactivity and Parallelism in Grids: Support of Advanced Applications across Distributed Infrastructures

We describe the recent achievements of the project interactive European grid in the area of middleware development oriented to advanced application support. These enhancements concern mainly support to MPI parallel execution on the grid, interactivity and fast job allocation. Support to MPI has been achieved by using an intermediate layer called MPI-start which provides reliable support to parallel execution both, at the intra-cluster and inter-cluster level. Interactivity, visualization and the combination of both to construct the support for simulation steering has been achieved by using an enhanced version of glogin and the grid visualization protocol GVid. We show with a few examples how the combination of all these features provides a very complete working environment for application developers and end users.