Skype for Business (or SfB;formerly Microsoft Office Communicator and Microsoft Lync) and Microsoft Lync for Mac are instant-messaging clients used with Skype for Business Server or with Lync Online (available with Microsoft Office 365). They replace Windows Messenger, which ran with Microsoft Exchange Server. Both Microsoft Lync and Microsoft Lync for Mac are enterprise software; compared to Windows Live Messenger and later Skype, they have different features that target businesses. On 11 November 2014, Microsoft announced that in 2015, Skype for Business would replace Lync. The latest version of the communication software combines features of Lync and of the consumer software Skype. There are two user interfaces – organizations can switch their users from the default Skype for Business interface to the Skype for Business (Lync) interface.