Windows Live Messenger (WLM), still commonly referred to by the previous name of MSN Messenger (MSN for short), is an instant messaging client for Windows XP, Windows Server 2003, Windows Vista, and Windows Mobile, first released on December 13, 2005 by Microsoft. It is part of Microsoft's Windows Live set of online services. The current version is Windows Live Messenger 8.5, which was released on November 6, 2007.