distributed.net is a loosely knit group of computer users from all of the world that is taking up challenges requiring lots of computing power (most notably the RC5, DES, and OGR cracking contests). It is simple to participate in the challenges by downloading and running their client software (which uses idle CPU time to complete its tasks).
PVM (Parallel Virtual Machine) is a portable message-passing programming system, designed to link separate host machines to form a ``virtual machine'' which is a single, manageable computing resource. The virtual machine can be composed of hosts of varying types, in physically remote locations. PVM applications can be composed of any number of separate processes, or components, written in a mixture of C, C++ and Fortran. The system is portable to a wide variety of architectures, including workstations, multiprocessors, supercomputers and PCs.
Xi-Batch is a very flexible job scheduling and workload management system. It provides time-based scheduling as well as load management, dependency-based job execution, and job prioritization. Each job's environment (environment variables and I/O default paths) is established by the system based on user ID. It can manage jobs in a single server or across a network of any number of servers, even different UNIX/Linux platforms. It can be controlled by CLI, a GUI (Motif), A Windows client, a Web-browser, or through an API. It works as an intelligent job dispatcher in grids or other server clusters.
Moab Workload Manager is a High Performance Computing (HPC) resource management and job scheduler. It is designed and developed by the same developers as the popular Maui Scheduler, and it provides the same powerful cluster scheduling capabilities with the addition of events, resources, and grid policy engines.