AFAIK, at least for now it is.<p>Libraries on Linux and OS X just are different. Maybe when core libraries [0] will be fully finished we could just use `import Foundation` on both platforms.<p>[0] <a href="https:&#x2F;&#x2F;swift.org&#x2F;core-libraries&#x2F;" rel="nofollow">https:&#x2F;&#x2F;swift.org&#x2F;core-libraries&#x2F;</a>