Introducing HyperDB, a P2P and versioned distributed key-value store written in JavaScript that allows you to share huge datasets but only replicate the data you are interested in securely and fast.
Mathias is a non-profit Node.js hacker based in Copenhagen, Denmark. He works full time on open source and in the Dat project, http://dat-data.com trying to build open tools to help scientists share datasets. Currently he maintains more than 400 modules on npm including a bunch of P2P and mad science stuff.