Baïkal is a lightweight CalDAV+CardDAV server. It offers an extensive web interface with easy management of users, address books and calendars. It is fast and simple to install and only needs a basic php capable server. The data can be stored in a MySQL or a SQLite database.

• Baïkal @ GitHub.

Related contents:

• Stop Uploading Your Data to Google @ ignore the code.
• Why Self-host? @ Roman Zipp.

eMail query-command to use vCards in mutt and Vim.

vdirsyncer is a command-line tool for synchronizing calendars and address books between a variety of servers and the local filesystem. The most popular use case is to synchronize a server with a local folder and use a set of other programs to change the local events and contacts. vdirsyncer can then synchronize those changes back to the server.

• vdirsyncer @ GitHub.

Secure Data Sync.

Secure, end-to-end encrypted, and privacy respecting sync for your contacts, calendars, tasks and notes.

Easy to use and open source - it seamlessly integrates with your existing apps so you won't even notice you are using it!

• EteSync server @ GitHub.
• etesync-dav @ GitHub is a CalDAV and CardDAV adapter for EteSync.