Notes on Apple's Rosetta Technology

With Apple transitioning the entire Macintosh line over to Intel processors over the next 12 months, users will have to be familiar with Rosetta. Rosetta is the emulator (translator) that allows current Mac (PowerPC) programs to run under the new Intel processors.

Apple has posted some recent developer notes about Rosetta which may be of interest to users.

Rosetta supports "applications that run on the PowerPC G3 or G4 processor that are built for Mac OS X". This excludes the following applications:

- Classic Environment, and subsequently any Mac OS 9 or earlier applications
- Screensavers written for the PowerPC
- System Preference add-ons
- Applications which specifically require the PowerPC G5
- Kernel extensions
- Java applications with JNI (PowerPC) libraries

As developers compile their applications for the new Intel processors, they will be releasing all new applications as Universal Binaries. Universal Binaries have both PowerPC and Intel code and can be used on either type of Mac.

You can tell if an application is is Universal or PowerPC by opening the Info window in finder. (example)