The Subnodes project is an open source initiative focused on streamlining the process of setting up a Raspberry Pi as a wireless access point for distributing content, media, and shared digital experiences. The device behaves as a web server, creating its own local area network, and does not connect with the internet. This is key for the sake of offering a space where people can communicate anonymously and freely, as well as maximizing the portability of the network (no dependibility on an internet connection means the device can be taken and remain active anywhere). The devices are also mesh enabled, implementing the BATMAN Advanced routing protocol.
So far, SubNodes has been used to set up small-scale art installations and demo projects including a chat room called Hot Probs which acted as a kind-of private network agony aunt, which runs on a Raspberry Pi. Read more about the project and the system here.