See entropia.com for an existing large distributed network. Their proof-of-concept network is the backend for The Great Internet Mersenne Prime Search. Newly activated second generation network is doing AIDS research using molecular modelling – see fightaidsathome.org.

The GIMPS clients have available source, except the actual client/server protocol, but so far the Entropia 2.0 clients have all been closed source (and, so far, all for Windows – sigh).

There is a Wired News article on this: Protein Fiends Join the Fold, which discusses:

So, as I commented in the Nano@Home proposal , this is much more expensive than the evolving design of simple nanoparts, where a single machine can do all of the necessary computations. It does mean however, that if enough people get involved in Nano@Home, the Folding@Home algorithms may provide a path for NanoSimulations@Home to test nanoparts aggregated into nanomachines.

One observer on Slashdot pointed out the code being released, like SETI@Home, is binary. While it is coming from an academic lab, some people and corporations will not run it because they cannot verify it is secure. Perhaps after some of their papers are published, they may make it open source. One can hope.

In a positive direction, they reveal work of the Mithral Client-Server SDK which could enable a more rapid development of distributed nanomodeling projects.