Inferno (http://code.google.com/p/inferno-os/) is a system which can be hosted on many different architectures and can be used for distributed computing.
InfernoTutorial This is a good place to start to learn the basics
InstallingInferno More detailed installation instructions for different platforms
Presentation about Inferno Michael Jeffrey (CEO of Vita Nuova) gave a talk to the Reading e-Science Centre on March 25th 2004. These are his slides (HTML format).
InfernoGuides Guides to doing useful things in Inferno
InfernoWorkflowExperiment Experiment with creating and composing simple remote services in Inferno. Is this suitable as a replacement for a Web Services architecture?
http://www.gemusehaken.org/ipwl/ Source code from "Inferno Programming with Limbo" - code is from an older version of Limbo, but many examples are still valid