Syncthing

Syncthing is a continuous file synchronization program. It synchronizes files between two or more computers in real time, safely protected from prying eyes. Your data is your data alone and you deserve to choose where it is stored, whether it is shared with some third party, and how it's transmitted over the internet.

Main Features:

Private & Secure

• Private. None of your data is ever stored anywhere else other than on your computers. There is no central server that might be compromised, legally or illegally.
• Encrypted. All communication is secured using TLS. The encryption used includes perfect forward secrecy to prevent any eavesdropper from ever gaining access to your data.
• Authenticated. Every node is identified by a strong cryptographic certificate. Only nodes you have explicitly allowed can connect to your cluster.

Open

• Open Protocol. The protocol is a documented specification - no hidden magic.
• Open Source. All source code is available on GitHub - what you see is what you get, there is no hidden funny business.
• Open Development. Any bugs found are immediately visible for anyone to browse - no hidden flaws.
• Open Discourse. Development and usage is always open for discussion.

Easy to Use

• Powerful. Synchronize as many folders as you need with different people or just between your own devices.
• Portable. Configure and monitor Syncthing via a responsive and powerful interface accessible via your browser. Works on Mac OS X, Windows, Linux, FreeBSD, Solaris and OpenBSD. Run it on your desktop computers and synchronize them with your server for backup.
• Simple. Syncthing doesn't need IP addresses or advanced configuration: it just works, over LAN and over the Internet. Every machine is identified by an ID. Give your ID to your friends, share a folder and watch: UPnP will do if you don't want to port forward or you don't know how.

Note: While the software is classified as free, it is actually donationware. Please consider making a donation to help support development.