Longhorn and Win2k3 shouldn't be compared at all. Longhorn is a client OS, Windows XP's successor. Windows Server 2003 is the successor to the Windows 2000 Server family. Put it this way, if I wanted a client platform for multimedia and gaming, I would use Windows XP. If I wanted to run a webserver with over 10 concurrent connections, along with FTP, NNTP and SUS, then Windows Server 2003.