MSN is owned by Microsoft and is the default home page for the Internet Explorer Browser. MSN is presently developing a new search platform for the MSN portal. Presently primary results are provided by Inktomi (Yahoo!) with PPC results from Overture (another Yahoo! property). Until January of 2004, MSN was getting primary results from LookSmart, with Inktomi feeding in supplemental data. MSN has both domestic and international sites and portals. The international portal affiliations are to provide algo and/or PPC (through Overture) results.
Recently they have made a few announcements about the new search platform. A spider called MSNBot has started crawling to produce a free index. There have been rumors of integration with the Windows operating system and a constant rumor of developing their own PPC platform though they continue to speak highly of Overture despite its recent purchase by Yahoo!.

MSN adCenter - MSN PPC Program
MSN is officially announcing MSN adCenter, the next generation Microsoft online advertising platform....

MSN Newsbot
MSN has Recently Announced that they have upgraded it's Newsbot....