In June 2009, Microsoft reported the service attracted over 330 million active users each month, placing Messenger among the most widely used instant messaging clients in the world. It has since been officially known by its second name, although its first name was still used colloquially by most of its users. The client was first released as MSN Messenger Service on July 22, 1999, and was marketed under the MSN branding until 2005 when it was rebranded under Windows Live.
It connected to the Microsoft Messenger service while also having (as of the final version) compatibility with Yahoo! Messenger and Facebook Messenger.
MSN Messenger (colloquially known as simply MSN ), later rebranded as Windows Live Messenger, was a cross-platform instant messaging client developed by Microsoft.
