Windows Live Messenger (formerly MSN Messenger) is an instant messaging client created by Microsoft that is currently designed to work with Windows XP, Windows Vista, Windows Server 2003, Windows Server 2008, and Windows Mobile. Since 2005, it has been part of Microsoft's Windows Live set of online services. It connects to Microsoft's .NET Messenger Service.

The client was first released as MSN Messenger on July 22, 1999,Microsoft Launches MSN Messenger Service and as Windows Live Messenger on December 13, 2005.Windows Live Messenger release dates from official blog The currently available final release is Windows Live Messenger 8.5, which was released on November 6, 2007. Windows Live Messenger 2009 is currently in development.

Features

In addition to its basic functionality and general capability as an instant messaging client, Windows Live Messenger offers the following features:

Sharing folders

The Sharing Folder feature of Windows Live Messenger is an alternative to the "direct transfer" method of file distribution. When a user wants to deliver a file to another person on his or her contact list, the "sharing folder" window appears, which is an individualized representation of all previously shared items.

When files are added to the "sharing folder" for that particular person, the file will automatically be transferred to the corresponding computer when they are online. This means that the folder is literally "shared" between two computers. If a user deletes a file, for example, the file will also be deleted from the corresponding computer's shared folder.

To minimize risk of virus-infected transfers, the "sharing folder" feature is bundled with an anti-virus program. The "sharing folder" feature can only be used on computers with NTFS-formatted hard disks.

PC-to-phone calls

main: Windows Live Call

In addition to PC-to-PC calls that have been supported in previous versions, Windows Live Messenger now supports PC-to-phone calls with Windows Live Call. In the US, this feature is supported by Verizon, branded as "Verizon Web Calling". Orange France also has a similar service. This feature is only available in selected countries, including the US, the UK (Verizon ended service in August 2008), France, Germany, the Netherlands, Austria, Ireland, Finland, Belgium, Spain, and Italy.

Interoperability

On October 13, 2005, Yahoo! and Microsoft announced plans to introduce interoperability between their two messengers, creating the second largest instant messaging user base worldwide: 40 percent of all users. The announcement comes after years of third-party interoperability success (most notably, Trillian, Pidgin) and criticisms from Google that the major real time communications services were locking their networks.