CardDAV

CardDAV is an address book client/server protocol designed to allow users to access and share contact data on a server.

Protocols
Anonymity
I2P
Tor
Communication
DNS
IRC
Matrix
SIP
Tox
XMPP
Encryption
GPG
OMEMO
OTR
S/MIME
SSL/TLS
ZRTP
Synchronization
ActiveSync
CalDAV
CardDAV
WebDAV
Syndication
RSS