Microsoft Lync (formerly Microsoft Office Communicator) and Microsoft Lync for Mac are instant messaging clients used with Microsoft Lync Server or Lync Online available with Microsoft Office 365. They are replacements for Windows Messenger, which was used with Microsoft Exchange Server.
Both Microsoft Lync and Microsoft Lync for Mac are enterprise software; unlike Windows Live Messenger (and later Skype), they have a different feature set that is targeted toward corporate environments.
On 11 November 2014, Microsoft announced that in 2015 Lync will be replaced by Skype for Business. The next version of the communication software will combine features of Lync and the consumer Skype software.
• instant messaging
• Voice Over IP (VoIP)
• video conferencing inside the client software
• availability of contacts based on Microsoft Outlook contacts stored in a Microsoft Exchange Server
• users can retrieve contact lists from a local directory service such as Microsoft Exchange Server
• Microsoft Office can show if other people are working on the same document
• All communication between the clients takes place through a Microsoft Lync Server. This makes communications more secure, as messages do not need to leave the corporate intranet, unlike with the Internet-based Windows Live Messenger. The server can be set to relay messages to other instant messaging networks, avoiding installation of extra software at the client side.
• A number of client types are available for Microsoft Lync, including mobile clients.• uses SIP as the basis for its client communication protocol
• offers support for TLS and SRTP to encrypt and secure signaling and media traffic
• allows sharing files.