Syncthing is a free and open-source file synchronization client-server application implementing its own block exchange protocol. It replaces proprietary sync and cloud services (such as DropBox) with something open, trustworthy and decentralized. The source code of Syncthing is available under the Mozilla Public license version 2.0.
Syncthing Periodic #1: Jakob Borg https://forum.syncthing.net/t/syncthing-periodic-1/5629
Syncthing Periodic #2: Jakob Borg https://forum.syncthing.net/t/syncthing-periodic-2/5680