The behavior of fork(), when not linked to the -lpthread library, might change in a future release. This behavior change makes Solaris threads consistent with Portable Operating System Interface (POSIX) threads.
The fork() function might be redefined to behave like fork1(). Therefore, fork() would replicate only the calling thread in the child process. This redefinition matches the current behavior of fork1() and of fork() when linked with -lpthread.
Support for applications that require the replicate-all behavior of fork() would still be provided.