Thank you Steven for your help. I have incorporated your patch into the code as shown in trac. This time the library compiled well. The compiler I use is: bash-3.2$ CC -V CC: Sun Ceres C++ 5.10 SunOS_i386 2009/03/06 Usage: CC [ options ] files. Use 'CC -flags' for details A little side node: The code sample I used is from the boost documentation of the thread's library at: http://www.boost.org/doc/libs/1_39_0/doc/html/thread/time.html Here's the code: int main(int argc, char** argv) { boost::system_time const timeout = boost::get_system_time() + boost::posix_time::milliseconds(500); extern bool done = true; extern boost::mutex m; extern boost::condition_variable cond; boost::unique_lockboost::mutex lk(m); while (!done) { if (!cond.timed_wait(lk, timeout)) { throw "timed out"; } } return (EXIT_SUCCESS); } But as with the code provided on the net (see link above) where the variables (done, m, cond) are specified with extern, the linker always moaned that it couldn't resolve those symbols. So IMHO this example is not well suited for a standalone example. -Roman