Mozilla has started working on a new iOS browser that uses the company’s Gecko rendering engine instead of Apple’s mandatory WebKit. The company confirmed in a statement shared with The Register that it’s doing “exploratory work” in case Apple is planning to change its App Store rules currently preventing third-party web browsers to use the rendering engine of their choice.

“We abide by Apple’s iOS app store policies, and are simply doing some exploratory work to understand the technical challenges for Gecko-based browsers on iOS if those policies were to change,” a Mozilla spokesperson said. “We hope the day will come when people can freely decide to use the browser of their choice, including the opportunity to select the engine that underpins it.”

The Register reported last week that Google was doing a very similar thing: The Chrome maker has also started work on a new iOS web browser that uses Blink, the same rendering engine that Chrome and other Chromium-based web browsers use. “This is an experimental prototype that we are developing as part of an open source project with the goal to understand certain aspects of performance on iOS,” a Google spokesperson said.

As of today, Apple requiring all third-party web browsers on iOS to use its WebKit rendering engine isn’t great for competition and security. Mozilla, Google, and Microsoft can offer a different UI and UX in their web browsers, but any WebKit vulnerability or compatibility issue that affects Apple’s Safari web browser will also affect third-party web browsers on iOS. That’s not the case on Android, where, for example, the Android version already uses Mozilla’s own Gecko engine.

In Europe, the Digital Markets Act will soon require Apple and other “gatekeepers” to allow third-party App Stores, which means that iOS web browsers that don’t use WebKit will finally be allowed. Bloomberg also reported in December that Apple may finally drop the requirement for third-party web browsers in the App Store to use WebKit, and that change may come with iOS 17 next year.