syncthing

Prioritizes preventing file corruption with mechanisms to protect user data, as outlined in its primary goal of being 'safe from data loss'.

Implements encryption to secure data against eavesdropping and unauthorized access, ensuring it's 'secure against attackers' as a core design principle.

Synchronizes files with minimal user interaction, operating continuously in the background to fulfill the 'automatic' goal.

Runs on all common operating systems including Windows, macOS, and Linux, supporting the 'universally available' objective.

Uses peer-to-peer architecture without central servers, giving users full ownership of their data and aligning with its focus on individuals.