Mac Address Book is an address book for Apple’s Mac OS X. It features various syncing features and integrations into the rest of the OS. Address Book also supports Lightweight Directory Interchange Format (LDIF). LDIF is an ASCII file format used to exchange information and enable synchronization of that information between Lightweight Directory Access Protocol (LDAP) servers. You can’t export information from Address Book in LDIF format; you can only import it. Address Book can import and export vCards. Yahoo! Address Book is an online contact manager you can …