Page "A/UX" Paragraph 3

By including a compatibility layer, A / UX could run Macintosh System 7. 0. 1, Unix, and " hybrid " applications.

A hybrid application used both Macintosh and Unix system functions: for example, a Macintosh application which called Unix system functions, or a Unix application which called Macintosh Toolbox ( e. g. QuickDraw ) functions.

The compatibility layer used some existing Toolbox functions in the computer ’ s ROM, while other function calls were translated into native Unix system calls.