Hello... > User-level threads is usually used to mean "the user-space library > creates some kind of threads inside a single process". Ie. the > threads NOT created with clone(). In this sense, pthreads do NOT > create user-level threads. They create kernel-level threads. Which > are not to be confused with kernel threads. I just hope my previous explanation doesn't confuse Tayser. However just want to point out, for non UNIX example of such user-level thread, take a look on Windows fibre. It is a schedulable entity that completely live in user space only and scheduled in cooperative style. From scheduler point of view, Windows Fibres are just a single process managed by one kernel level thread. regards Mulyadi -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/