Xbox maker Microsoft has come to the defence of Epic Games in its lawsuit against Apple.

In a declaration to the District Court for the Oakland division of the Northern District of California – as reported by The Verge – the Big M's GM of gaming developer experiences Kevin Gammill said that Apple's threat to deny Epic access to its SDKs would harm developers using the company's Unreal Engine.

Whether or not Epic's tech will still be supported on iOS and MacOS platforms makes it less likely for Microsoft to use Unreal.

"Even uncertainty about the Unreal Engine’s ability to continue supporting iOS and macOS will make it less likely for Microsoft (and, I believe, other game creators) to select Unreal Engine for their projects," Gammill wrote.

"When game creators are planning development projects, which can last for years, it is important to have confidence that the chosen engine will continue to be available on and support all platforms on which the game creators plan to distribute their games.

"Apple’s discontinuation of Epic’s ability to develop and support Unreal Engine for iOS or macOS will harm game creators and gamers."

This follows Epic suing both Apple and Google over antitrust, with the company alleging that both of these platforms are monopolies.