Linux threads is an POSIX pthreads implementation using "kernel
threads".  In this FreeBSD port, a kernel thread is started using
rfork (whereas in the original Linux implementation a kernel thread
is started using the Linux clone call).  This implementaion provides
a so-called one-to-one mapping of threads to kernel schedulable
entities. For more information see about the original linux threads
implementation see:

	http://pauillac.inria.fr/~xleroy/linuxthreads/