Example: "Rosetta allowed the user to run Microsoft Word 2004 on his new Mac Pro."
Rosetta is technology included in Mac OS X that allows software written for PowerPC processors to run on Intel processors. It translates the instructions in PowerPC programs into commands that can be recognized by an Intel-based Macintosh.
Rosetta runs behind the scenes, so the user does not see it working. However, because dynamically translates commands from PowerPC to Intel, users may notice some slowdown when running PowerPC programs on Intel-based Macintosh computers.