vdirsyncer

Vdirsyncer is a command-line tool for synchronizing calendars and contacts across multiple servers and local storage. Developers use it to keep calendar and addressbook data in sync between services like CalDAV and CardDAV servers, as well as the local filesystem. The typical workflow involves synchronizing a remote server with a local folder, making changes to events and contacts locally, then syncing those modifications back to the server. Beyond server-to-client synchronization, vdirsyncer can also synchronize calendars and addressbooks directly between two servers.

The tool is developed by pimutils and is written in Python. It operates as a command-line utility and supports various calendar and contact formats including iCalendar and vCard standards. The project includes comprehensive documentation covering installation, configuration, SSL certificate validation, password storage, and synchronization with read-only storages.