Decentralized tech

Messaging

• patchwork - A decentralized messaging and sharing app built on top of Secure Scuttlebutt (SSB). https://www.scuttlebutt.nz

File storage

• syncthing
• gridsync - Synchronize local directories with Tahoe-LAFS storage grids

Databases

• hyperdb - Distributed scalable database

Other

• alternative-internet - A collection of interesting new networks and tech aiming at decentralisation (in some form).