Hi, I'm trying to find a production quality lock free reference counted pointer implementation and boost::shared_ptr seems promising. However boost::atomic_is_lock_free(shared_ptr) returns false on Windows. I'm going to try on SUSE linux soon. According to http://www.boost.org/doc/libs/1_43_0/libs/smart_ptr/shared_ptr.htm, Starting with Boost release 1.33.0, shared_ptr uses a lock-free implementation on the following platforms: GNU GCC on x86 or x86-64; GNU GCC on IA64; Metrowerks CodeWarrior on PowerPC; GNU GCC on PowerPC; Windows. Then why does boost::atomic_is_lock_free(shared_ptr) returns false? Is there any compiler flag that needs to be set? I also found another lock free reference counted pointer, atomic_ptr from Joe Seigh here http://sourceforge.net/projects/atomic-ptr-plus/files/ but it seems to support linux with GCC only. Documentation is also poor. -Anqing