Other Dark / Overlay Networks

Other Lists

http://en.wikipedia.org/wiki/List_of_wireless_community_networks_by_region
http://en.wikipedia.org/wiki/Darknet_(networking) https://en.wikipedia.org/wiki/Category:Anonymity_networks
http://anonet2.biz/List%20of%20Anonymous%20Networks
https://en.wikipedia.org/wiki/Anonymous_P2P

Tor (The onion router) is an anonymity network that also features a darknet - its "hidden services". It's the most popular instance of a darknet.

I2P (Invisible Internet Project) is another overlay network that features a darknet whose sites are called "Eepsites".
Freenet is a popular darknet (friend-to-friend) by default; since version 0.7 it can run as a "opennet" (connecting to untrusted users).
RetroShare can be run as a darknet (friend-to-friend) by default to perform anonymous file transfers if DHT and Discovery features are disabled.
GNUnet is a darknet if the "F2F (network) topology" option is enabled.
Syndie is software used to publish distributed forums over the anonymous networks of I2P, Tor and Freenet. OneSwarm can be run as a darknet for friend-to-friend file-sharing.
Tribler can be run as a darknet for file-sharing.