Mac OS X Softwares to Address book integration

BusyCal is a powerful desktop calendar application for Mac, designed to enhance productivity and organization. It offers a robust set of features for managing events, tasks, and reminders, with seamless integration across various calendar services like iCloud, Google Calendar, and Exchange.

Soocial was a cloud-based synchronization service designed to keep your contacts consistent and up-to-date across various devices, applications, and platforms, including computers, phones, and web services.

Contacts is a fundamental contact management application designed for macOS, providing seamless integration within the Apple ecosystem for organizing and managing personal and professional connections.

Telephone is a user-friendly SIP softphone application for macOS that enables encrypted voice calls over the internet or a private network. It supports various codecs and offers features like call recording, address book integration, and secure communication.

Blink is a robust, real-time communications client leveraging the SIP protocol for secure and private instant messaging, voice, and video calls. It emphasizes features like end-to-end encryption, file sharing, and screen sharing across various platforms.

Zoiper is a versatile and easy-to-use SIP softphone designed for clear voice and video communications. It offers excellent audio quality, robust security features, and seamless integration with various communication protocols, making it ideal for personal and business use.

KMail is a powerful and flexible email client tightly integrated with the Kontact personal information manager suite. Part of the KDE ecosystem, it offers robust features for managing your email, including strong encryption options, support for multiple protocols like IMAP, POP3, and Exchange, and seamless integration with other Kontact components like the calendar and address book.

Mutt is a highly configurable, text-based email client for Unix-like systems. It offers powerful features for advanced users who prefer a lightweight and efficient email management experience directly from the command line.

Nylas Mail, an extensible open-source email client, offers a unified inbox, robust search, and calendar integration. It supports multiple accounts and provides features like email tracking and undo send, aiming to enhance productivity and email management for users.

Inky is a feature-rich email client prioritizing security and a clean interface across Windows, macOS, iOS, and Android. It offers seamless multi-account management, robust privacy features including encryption, and integrations for enhanced productivity and organization.

Opera Mail, formerly known as M2, is a versatile and lightweight email and news client developed by Opera Software. It offers a unified approach to managing email, news feeds, and contacts with a strong emphasis on organization and speed.

Apple Calendar is a personal calendar application developed by Apple Inc., designed to seamlessly integrate with your Apple ecosystem whether you are on macOS or iOS. It allows you to manage your schedule, appointments, and events efficiently, synchronizing across all your devices.

Postbox is a powerful and customizable email client designed for professionals managing high volumes of email. It offers robust features for organizing, searching, and managing multiple accounts efficiently, enhancing productivity through a clean interface and advanced tools.

Zimbra Desktop provides a unified interface for managing multiple email accounts, calendars, tasks, and contacts offline. It supports various protocols like IMAP, POP, CalDAV, and CardDAV, offering a comprehensive personal information management solution.

Apple Mail is the default email client for macOS, iOS, and watchOS, offering a seamless and integrated email experience across Apple devices with features like rich text editing, multiple account support, and robust organization tools.

Microsoft Outlook is a comprehensive personal information manager designed for managing email, contacts, calendars, and tasks.