Notes on Apple's Rosetta Technology - MacRumors
Skip to Content

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)

Popular Stories

macbook ultra

'MacBook Ultra' Coming Soon With These 12 New Features

Friday July 24, 2026 6:00 pm PDT by
Apple's first high-end MacBook redesign in five years is expected to arrive in the near future, bringing a run of firsts to the Mac. Bloomberg's Mark Gurman expects the laptop to arrive between late 2026 and early 2027, with the later window now looking more likely owing to the global memory chip shortage. Analyst Ming-Chi Kuo expects mass production to begin by late 2026. Apple last...
iPhone 18 Pro Deep Red Feature

iPhone 18 Pro Launching in Two Months With These 12 New Features

Friday July 24, 2026 7:26 pm PDT by
It is now late July, and that means the iPhone 18 Pro and iPhone 18 Pro Max are less than two months away. The devices are expected to look similar to the iPhone 17 Pro and iPhone 17 Pro Max, but there will still be many year-over-year changes, with rumored features including a smaller Dynamic Island, 5G via satellite, and more. Apple is expected to unveil the iPhone 18 Pro, iPhone 18 Pro...
5 Reasons to Buy the iPhone 17 Now Feature

5 Reasons to Buy the iPhone 17 Now Instead of Waiting for iPhone 18

Thursday July 23, 2026 8:26 am PDT by
Apple's iPhone 18 Pro models and its first foldable are less than two months from being unveiled. That may sound like a reason to sit tight if you're looking to upgrade from an iPhone 16 or older series, but between looming price hikes and Apple's new split-launch calendar, there's a decent case for grabbing an iPhone 17 series model right now. Here are five reasons in favor of putting your order ...