How do you spell Hannukah?
An executable file containing code for more than one CPU. The correct code is selected automatically at run time. This is convenient for distributing software and sharing it between multiple platforms.
NEXTSTEP supports fat binaries, e.g. for Motorola 68000, Intel 80486 and SPARC ("triple fat"). Mac OS supports fat binaries for both 680x0 and PowerPC native code.