[ excerpt from developer's web site ]

I2P is an anonymizing network, offering a simple layer that
identity-sensitive applications can use to securely communicate.
All data is wrapped with several layers of encryption, and the
network is both distributed and dynamic, with no trusted parties.

Many applications are available that interface with I2P, including
mail, peer-peer, IRC chat, and others.

Anonymity is not a boolean - we are not trying to make something
"perfectly anonymous", but instead are working at making attacks
more and more expensive to mount. I2P alone is what could be called
a "low latency mix network", and there are limits to the anonymity
offered by such a system, but the applications on top of I2P, such
as Syndie, I2P mail, and I2PSnark extend it to offer both additional
functionality and protection.

WWW: http://www.i2p2.de/