Multiprocessing Services in Mac OS 9 and Mac OS X

Multiprocessing Services 2.1 runs on system software Mac OS 9 and later. All PowerPC Macintosh computers are supported..

Multiprocessing Services 2.1 is packaged as part of the Mac OS System file, so you cannot install version 2.1 on older versions of system software.

Multiprocessing Services allows your application to create preemptive tasks within your application's process (or execution context). However, the individual applications are still cooperatively scheduled by the Process Manager. In Mac OS X, both applications and tasks created by applications will be preemptively scheduled. Multiprocessing Services is Carbon-compliant, so applications built following the Carbon specification can run transparently on both Mac OS 8 and Mac OS X systems.