> Thread Library is a free library, for use by Macintosh software
> developers, that implements cooperative multiple thread execution
> within a single application. Thread Library...
>
>   * does not require any extensions
>   * should work with all Macintosh models (from the Plus on up)
>   * works with system 7.x and with system 6.x under Finder or
> MultiFinder
>   * runs in native mode on 680x0 and PowerPC* based Macintoshes
>   * compiles into a small library of 3 to 8 kilobytes
>   * works with the Symantec, Metrowerks, and MPW compilers
>

>
> The 680x0 version of Thread Library is 2-3 times faster than Apple's
> Thread Manager. The PowerPC version of Thread Library is about 2
> times faster than Apple's Thread Manager.
>
> Every thread has its own stack, and there are no restrictions on the
> objects that can be allocated on a thread's stack. All other global
> application data are shared by threads. Context switches are very
> efficient since they involve only a few operations to save the
> current thread's state, followed by a context switch to the new
> thread, and a few instructions to restore the new thread's state.

The "threadlib1.0.sit_.hqx" archive includes:

 * complete source code in C
 * detailed documentation in Microsoft Word 5.0 format
 * prebuilt libraries for 68K and PowerPC programs, including debug
   versions of the libraries
 * a new interface that mimics Apple's Thread Manager
 * a simple test application that demonstrates how threads may be
   used
 * an application that compares the speed of Thread Library with the
   speed of Apple's Thread Manager
 * Metrowerks CodeWarrior project files
 * AppleScript program for automatic builds

The "threadlib1.0d4.cpt_.hqx" archive is an earlier release, from
1994, included for historical reasons.

Historical Note
Apple Trademark guides specify that MacDNS end-user documentation
should include "ThreadLib 1.04 � 1994" notice, suggesting that version
of ThreadLib was used in at least one Apple product

Compatibility
Architecture: 68k PPC

Mac Plus and better; 6.x and later