Microsoft Lync Server (previously Microsoft Office Communications Server) is an enterprise real-time communications server, providing the infrastructure for enterprise instant messaging, presence, file transfer, peer-to-peer and multiparty voice and video calling, ad hoc and structured conferences (audio, video and web) and, through a 3rd party gateway or SIP trunk, PSTN connectivity. These features are available within an organization, between organizations, and with external users on the public internet, or standard phones, on the PSTN as well as SIP trunking.

Microsoft Lync is the primary client application released with Lync Server. This client is used for IM, presence, voice and video calls, desktop sharing, file transfer and ad hoc conferences. Microsoft also ships the Microsoft Attendant Console. This is a version of the Lync more oriented towards receptionists or delegates / secretaries or others who get a large volume of inbound calls.

Other client software and devices include:

One basic use of Lync Server is instant messaging and presence within a single organization. This includes support for rich presence information, file transfer, instant messaging as well as voice and video communication. (These latter features are often not possible even within a single organization using public IM clients, due to the effects of negotiating the corporate firewall and network address translation). Lync uses Interactive Connectivity Establishment for NAT traversal and TLS encryption to enable secure voice and video both inside and outside the corporate network.

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 and Live@Edu. 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, they have a different feature set that is targeted toward corporate environments.

As of January 25, 2011 Microsoft Lync 2010 was generally available. The previous version was Office Communicator 2007 R2, released on March 19, 2009. An even earlier version, "Office Communicator 2007" was released to manufacturing on 28 July 2007 and launched on October 27, 2007. The full-featured desktop version of the client requires Windows 7, Windows Vista or Windows XP with Service Pack 2 or newer.

Microsoft Lync 2010 was released for the Windows Phone, Android and iOS platform in Dec 2011

There are a number of updates that have come out since the original release of the Lync client.

Coordinates: 47°38′22.55″N 122°7′42.42″W / 47.6395972°N 122.12845°W / 47.6395972; -122.12845

Microsoft Corporation (NASDAQ: MSFT) is an American multinational corporation headquartered in Redmond, Washington, United States that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions. Established on April 4, 1975 to develop and sell BASIC interpreters for the Altair 8800, Microsoft rose to dominate the home computer operating system market with MS-DOS in the mid-1980s, followed by the Microsoft Windows line of operating systems. Microsoft is one of the largest software corporations in the world.

Microsoft would also come to dominate the office suite market with Microsoft Office. The company has diversified into the video game industry with the Xbox and Xbox 360 consoles and the consumer electronics and digital services market MSN, the Zune and the Windows Phone OS. The ensuing rise of stock in the company's 1986 initial public offering (IPO) made an estimated three billionaires and 12,000 millionaires from Microsoft employees (Forbes 400 list revealed that in March 2011 both Jon Shipley and Nathan Myhrvold lost their billionaire status). In May 2011, Microsoft Corporation acquired Skype Communications for $8.5 billion.