First PC emulator arrives on iOS App Store, delivers i486 or PowerPC fun on your iPhone, iPad or Vision Pro

Despite Apple’s initial rejection of the emulator app and the developers’ initial decision to give up, UTM SE was approved and released on the App Store Sunday. The “retro PC emulator” allows you to run classic operating systems, software, and games on the iPhone, iPad, and Vision Pro.

UTM is a popular alternative on the Mac to applications like Parallels, VMWare, and VirtualBox. It acts as a graphical interface to the command-line-driven emulator Qemu. It’s never been officially available to iOS users, though, because Apple didn’t allow emulators of any sort on the iOS App Store until April 2024.

When Turing Software first submitted UTM SE to the App Store, Apple rejected the app. Apple also refused to notarize it for third-party app stores in the European Union. Part of the problem was that the app relied on Just In Time (JIT) compilation to provide a satisfactory emulation experience. JIT compilation means compiling code as a program is running rather than beforehand, something Apple deems a security risk on iOS.

Gaming emulators like DolphiniOS have also been rejected for needing JIT support. DolphiniOS depends on the technique to emulate newer Nintendo consoles. UTM used it to translate PowerPC code to run on the Arm-based chips found in current Apple devices.

Unwilling to resubmit the app without JIT support because doing so meant a subpar experience, it seemed as if UTM would not come to iPhones and iPads without jailbreaking the devices. However, help for the project came from another Qemu developer. Qemu is the actual emulation layer UTM uses to allow you to run software as if it was on an old i486 or PowerPC-based Mac.

The team implemented a version of the Qemu Tiny-Code Threaded Interpreter (TCTI). Qemu TCTI interprets the code rather than compiling it, allowing Turing Software to get around the JIT ban. Mind you, this results in a rather slow experience even by the standards of the emulated hardware. That’s why the app includes the “SE” tag at the end — “SE” stands for “Slow Edition.”

That being said, the approval is good news for other emulator developers. For the more general audience, you can install UTM SE from the App Store to run classic games or operating systems on emulated x86, PPC, and RISC-V architectures.