High performance file syncing and sharing, with also Markdown WYSIWYG ed...
:cloud: ownCloud web server core (Files, DAV, etc.)
Official frugal and native macOS Syncthing application bundle
Librevault - Peer-to-peer, decentralized and open-source file sync.
Differential file synchronization over http
Unison file sync web interface
Folder synchronization tool with a simple dashboard