What just happened? It seems that Apple just can't help itself when it comes to controlling what apps make it onto the iOS App Store. The company has claimed it is opening up to retro game emulators, but this month, it rejected updates to emulator apps iDOS and UTM, citing violations of its App Review Guidelines.

The new iDOS 3 release got shut down because emulating the ancient DOS operating system doesn't count as a "retro game console" under section 4.7 of the App Store guidelines. Apple allegedly couldn't explain what qualifies.

"When I asked what changes I should make to be compliant, they had no idea, nor when I asked what a retro game console is," Li said in a blog. "It's still the same old unreasonable answer along the line of 'we know it when we see it.'"

The app in question, iDOS, is a repackaged version of the open-source DOSBox emulator. The app has been available on the App Store since 2014, but in 2021, Apple removed it. With the loosened stance on emulators, Li has been trying to bring iDOS 3 to the platform, but Apple has blocked him.

The UTM emulator ran into similar issues trying to update its app to emulate vintage Windows and DOS games on iOS devices. The developer noted that the App Store review board determined that 'PC is not a console' after a two-month-long review process.

The UTM team's troubles didn't stop there. Apple also blocked the app from being notarized for distribution outside the App Store. The reason is guideline 2.5.2, which prohibits apps from executing external code to modify functionality. However, the app doesn't use the just-in-time compilation, which is the apparent issue.

The developers are understandably frustrated with Apple's inconsistent rule interpretations and lack of clear reasoning.

"As the sole rule maker and enforcer in [the] iOS ecosystem, they don't need to be consistent at all," Li told The Verge.

For its part, UTM has given up pursuing an App Store release, calling the experience "subpar" compared to third-party distribution channels – an option the EU has compelled Apple to allow through the Digital Markets Act.

Apple softened its stance on retro game emulators in April 2023 amid growing antitrust scrutiny over its App Store. It opened iOS to the popular emulators available on Android, with Delta being one of the first.