Windows Live Messenger (formerly named MSN Messenger, and often colloquially referred to as simply MSN) is an instant messaging client created by Microsoft that is currently designed to work with Windows XP, Windows Vista, Windows 7, Windows Server 2003, Windows Server 2008, and Windows Mobile. The client has been part of Microsoft's Windows Live set of online services since 2005. It connects to Microsoft's .NET Messenger Service. The client was first released as MSN Messenger on July 22, 1999, and as Windows Live Messenger on December 13, 2005.