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

• Display pictures
  
• Custom emoticons
  
• Multi-language support (around 40 languages currently supported)
  
• Webcam support
  
• Sign in to more than one account at once
  
• Full-speed File transfers
  
• Group support
  
• Normal, and animated emoticons with sounds
  
• Chat logs
  
• Timestamping
  
• Event alarms
  
• Conferencing support
  
• Tabbed chat windows
• Support for offline messaging
• Audio/Voice clips support
• Support for the MSN spaces
• A new and improved skin
• A new, fully skinnable contact list with background

For a full list, see the features page.
More features can be added to aMSN with plugins , or completely change its look with different skins!

More Info & Download: aMSN Messenger

aMSN 0.97.2 !
This version fixes, along with some other bugs, the bug you could have experienced when sending OIMs.

Download @ SourceForge