sync

Syncthing is an open-source peer-to-peer file synchronization tool that keeps your files synchronized between multiple devices without requiring a central server. It provides secure, private, and decentralized file sync with end-to-end encryption.

Seafile is a file hosting and sharing solution primarily designed for teams and organizations. It provides reliable file synchronization, sharing, and collaboration features with strong security and performance optimizations for enterprise use.

Unison is a file-synchronization tool for OSX, Unix, and Windows that allows two replicas of a collection of files and directories to be stored on different hosts and synchronized by detecting changes and propagating them in either direction.

Kinto is a minimalist JSON storage service with synchronization and sharing abilities. It provides a lightweight, schema-less storage solution with built-in synchronization capabilities, making it ideal for applications that need simple data storage and sync.

Host your own Firefox accounts server for managing Firefox Sync and other Mozilla services. It provides complete control over Firefox account management and synchronization services.

Pinepods is a podcast management system with multi-user support. It utilizes a central database so aspects like listen time and themes follow from device to device, providing a comprehensive self-hosted podcast platform with synchronization and personalization features.