aMSN is a free open source MSN Messenger clone, with features such as:

• Offline Messaging
• Voice Clips
• A New Login Window & Contact List (As of 0.97)
• Display pictures
• Custom emoticons
• Multi-language support (around 40 languages currently supported)
• Sign in to more than one account at once
• File transfers
• Group support
• Normal, and animated emoticons with sounds
• Chat logs
• Event alarms
• Conferencing support
• Webcam support
• History in color
• Ability to autoclose the filetransfer window when it is finished
• New plugins log window (Alt-P)
• Plugins compatible with supported languages
• Faster loading skin window
• Skins in chatwindow
• Resizable chatwindow bottom
• When you add a new user, you can define in which group you want to add them
• When a contact change status, the top of the chat window changes color ( green for away, grey for offline, etc.)
• New panel GUI to alert when there's a new aMSN version
• Possibility to download the new release directly by aMSN
• Automatically update language files and plugins from the web
• New gui for deleting users (also possible to block on deletion)
• Possible to add notes for each user (XML)
• Support for MSN Mobile service
• Tabbed windows so you can group conversations using tabs
• Status is displayed inside a frame, so it won't disappear when you scrolll
• Display picture in notification alert (like MSN 7)
• Statistics for history (logging)
• Now possible to choose any state for your login status (before it was only possible to login invisible or online)
• Timestamping

But that's not all! More features can be added to aMSN with plugins, or for the adventurous, completely change the look of aMSN with different skins!

Requirements:
OS X 10.3.9-10.6
Universal Binary