Microsoft Lync (formerly Microsoft Office Communicator) and Microsoft Communicator 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 Communicator for Mac are enterprise software; unlike Windows Live Messenger, they have an expanded feature set that is targeted toward corporate environments.