Retroshare

The InterPlanetary File System (IPFS) is a peer-to-peer hypermedia protocol network for storing and sharing data in a distributed file system.

ZeroNet is a decentralized web-like network of peer-to-peer users. Instead of having an IP address, sites are identified by a public key that allows the site owner to sign and publish changes.

Freenet is a peer-to-peer platform for censorship-resistant, anonymous communication by delivering information via a decentralized distributed data store.

The Invisible Internet Project (I2P) is a fully encrypted private network layer. It protects your activity and location. Anonymous connections are achieved by end-to-end encrypting the user's traffic.

GNUnet is a software framework for decentralized, peer-to-peer networking and an official GNU package. It offers link encryption, peer discovery, resource allocation, and more.

Tor, short for The Onion Router, is open-source software and the biggest cross-platform network available for enabling anonymous communication.