Turtle is a free anonymous peer-to-peer network project being developed at the Vrije Universiteit in Amsterdam, involving professor Andrew S. Tanenbaum (known for the MINIX operating system).

Technically, Turtle is a friend-to-friend (F2F) network - a special type of peer-to-peer network in which all your communication goes only to your friends, and then to their friends, and so on, to the ultimate destination.

The basic idea behind Turtle is to build a P2P overlay on top of pre-existing trust relationships among Turtle users. Each user acts as node in the overlay by running a copy of the Turtle client software.

Licensed under the GPL.

* http://en.wikipedia.org/wiki/Turtle_F2F
* http://www.turtle4privacy.org/