SAFMQ: Store and Forward Message Queue, message oriented middleware. Uses include Assured Async Messaging, SOA, Delayed/Batch, and Cluster/Grid Computing. The SAFMQ server provides cross platform communication among C++, PHP, Java, and .NET clients.
A community repository to develop Commodity Grid (CoG) Software for the access of Grids, through high level interfaces. The main repository is maintained at http://www.cogkit.org
Cluster101 allows you to run software on many hosts and perform a simple task scheduling. No need to install any software on the hosts (it just runs tasks via ssh). It is typically used for running scientific applications on University campuses.
The Gridbus Grid Service Broker, is a service-oriented, economy and data-aware resource broker system that uses a simple, extensible middleware independent architecture that mediates access to distributed resources on a local / Global Grid of computers.