Microsoft Messenger

Microsoft Messenger for Mac, styled as Microsoft Messenger:Mac[1] (previously MSN Messenger for Mac) is the official Mac OS X client for the .NET Messenger Service protocol and is developed by the Macintosh Business Unit, a division of Microsoft. However, the feature list is limited in comparison to that of its Windows Live Messenger. The client is still maintained and updated but still lacks a number of features that it's Windows counterpart contains. In response to its lack of features, numerous third-party competitors have been developed, such as Mercury Messenger and aMSN.

Versions
MSN Messenger for Mac v2.5.1 running under Classic emulation of Mac OS 9.2.2, under Mac OS X 10.4
The versions 3.x and later of Microsoft Messenger for Mac feature new Aqua graphics, whereas version 2.x and below have graphics similar to Windows Messenger 4.0. Versions 5.x use the brushed metal theme.
* Version 2.5.1 is an update to version 2.5, which is a mandatory update to version 2.1 that is available for users running Mac OS 9.2.2.
* Version 3.5 is available for Mac OS X revisions older to 10.2.8
* Version 4.0.1 is available for Mac OS X revisions newer than 10.2.8
* Version 5.1.1 is available for Mac OS X revisions 10.3 and newer
* Version 6.0.3 is available for Mac OS X revisions 10.3.9 and newer
* The latest version of Microsoft Messenger for Mac is 7.0, which was released on April 29, 2008 for Mac OS X v10.4.9 or newer.

It should be noted that with the release of Microsoft Messenger for Mac 7.0, Microsoft has discontinued the client's support for older versions of their Corporate messaging systems (such as Live Communications Server 2005). - The latest version to support these older systems is Version 6.03, which is still available for download on the Microsoft website.

Features
* Chat with Yahoo! Messenger contacts
* Status messages that personal contacts can see (can be set to show current song in iTunes)
* Full custom emoticon support, usable with personal contacts
* Send and receive custom animated emoticons with personal contacts
* Conversation history searchable with Spotlight
* Spellchecking in instant messages
* Personal and corporate (Microsoft Exchange) accounts
* Direct link to inbox
* Audio and Video chat (initially for Corporate accounts only)

Criticism
Microsoft Messenger for Mac is not as fully featured as Windows Live Messenger for Windows, lacking the following features:
* Handwritten messages
* Screen sharing
* Nudges
* Winks
* Photo backgrounds on current conversation windows
* Games that can be played with another contact
* Some built-in emoticons
* Contact details such as Nicknames and Addresses
* Integration with Windows Live Spaces
* Windows Live Today
* Automatic reconnection if connection is lost
* Sharing folders
* Color schemes
* Audio and Video chat for Personal accounts (this has been promised to feature later in the 7.x series)

Apple officially endorses use of the AOL Instant Messenger network via its own client iChat. Third-party applications, often able to connect to several instant messaging networks, offer Windows Live connectivity and sometimes more features like audio and video chat. aMSN for example, offers features such as Nudging, Voice Clips, and Video chat. This had led to widespread criticism of the Microsoft Mac Business Unit for not being able to release an instant messaging client that has more features than an open-source real time communications service.