CCF uses the .net localization system to support multiLingual support..
there are several good articles available on this subject on MDSN and other places... a good starting point is here : http://msdn.microsoft.com/msdnmag/issues/06/08/BasicInstincts/ While this article focus in on asp.net the principles are the same for smart clients.
here is a link to a search on the subject as well : http://search.live.com/results.aspx?q=.Net+Localization&src=IE-SearchBox
Matt B.