Started in 2013, 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. Your data is your data alone and you deserve to choose where it is stored, if it is shared with some third party and how it's transmitted over the Internet. The source code of Syncthing is available under the Mozilla Public license version 2.0. See also Why Syncthing.
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