NODEZILLA

Technically, Nodezilla is a secured, distributed and fault tolerant routing system. Its main purpose is to serve as a link for distributed services built on top of it (like chat, efficient video multicasting streaming, File Sharing, secured file store ...). Nodezilla provides cache features; any server may create a local replica of any data object. These local replicas provide faster access and robustness to network partitions. They also reduce network congestion by localizing access traffic. It is assumed that any server in the infrastructure may crash, leak information, or become compromised, therefore in order to ensure data protection, redundancy and cryptographic techniques are used.

http://www.nodezilla.net/

It's an OpenSource program, and I beleive it will be real interesting to have it on portable version.