The libraries in this directory are the same as "Server 2003\lib\x64".


Quote: 
------
"Note that the 64-bit vssapi.lib files in the directories under the Win2003\Obj directory
can be used for the 64-bit versions of Windows Server 2003 and Windows XP."

(Reference: http://msdn.microsoft.com/en-us/library/bb968832(VS.85).aspx)