str4d

I2P is an anonymous network, exposing a simple layer that applications can use to anonymously and securely send messages to each other. The network itself is strictly message based (ala IP), but there is a library available to allow reliable streaming communication on top of it (ala TCP). All ... [More] communication is end to end encrypted (in total there are four layers of encryption used when sending a message), and even the end points ("destinations") are cryptographic identifiers (essentially a pair of public keys). [Less]

I2P-Bote allows users to send and receive emails while preserving privacy. It does not need a mail server because emails are stored in a distributed hash table. They are automatically encrypted and digitally signed, which ensures no one but the intended recipient can read the email, and third parties cannot forge them.

Syndie is an open source system for operating distributed forums , offering a secure and consistent interface to various anonymous and non-anonymous content networks.