High Quality Content by WIKIPEDIA articles! Microsoft Messenger for Mac (previously MSN Messenger for Mac) is the official Mac OS X instant messaging client for use with Microsoft`s .NET Messenger Service and is developed by the Macintosh Business Unit, a division of Microsoft. However, the feature list is limited in comparison to that of its counterpart Windows Live Messenger. The client is still maintained and updated but still lacks a number of features that its Windows counterpart contains. However, several third-party applications that have support for the .NET Messenger Service, such as Trillian (software), Adium and aMSN, incorporate some of the features missing from the official client.