Freenet

Freenet is a free P2P network that is designed for free anonymous sharing of information and circumvention of censorship schemes.

Unlike other "hidden networks" such as I2P and Tor, Freenet is using an original transport protocol; while that doesn't allow for creation of dynamic websites, it allows the hosted contents to stay available even if the original hoster is not available.

The information is shared among multiple peers according to its popularity, so that content, once uploaded, will not be deleted as long as users are still interested in it.

Freenet's way of functioning has attracted users of many kinds, starting from hackers uploading their leaks and paranoidal editors from the whole political spectrum and ending with paedophiles uploading child pornography or anarchists' instructions on making explosives.