Hi The boost.atomic library is a header only library waiting for review (http://lists.boost.org/Archives/boost/2009/12/160195.php). There is a bug in the implementations of platform_atomic_thread_fence (all platforms) where it is not declared inline. This causes linker error when the library is used in different compilation units. Boost.atomic is being used in other libraries waiting for review such as boost.task which do not link for the same reason. Thank you. Best regards Jorge