The war between Epic Games and Apple is heating up, as allies join the fray.

Microsoft has filed a statement “in support of Epic’s request to keep access to the Apple SDK for its Unreal Engine”, according to a tweet by Xbox head Phil Spencer. Microsoft believes that Epic Games having access to the latest Apple technology is “the right thing for gamer developers & gamers”.

Spencer shared the official filing on Twitter, which was a declaration by Microsoft gaming developer general manager Kevin Gammill, which describes how harmful Apple’s actions would potentially not only for Microsoft, but the gaming industry as a whole.

Gammill states that Epic Games’ Unreal Engine is a “critical technology for numerous game creators including Microsoft.” While there are several companies or developers who have their own unique game engines (like EA’s Frostbite Engine or Guerrilla Games’ Decima Engine), Unreal Engine is one of the most widely-used development engines in the world.

In Microsoft’s view, there are very few other options for game engines that offer “as many functionalities as Unreal Engine across multiple platforms, including iOS”.

In addition, Microsoft has an “enterprise-wide, multi-year Unreal Engine license agreement and has invested significant resources and engineer time working with and customizing Unreal Engine for its own games on PC, Xbox consoles, and mobile devices (including iOS devices)”.

If Apple goes forward with their move to block Epic Games from the iOS platform, it would “place Unreal Engine and those game creators that have built, are building, and may build games on it at a substantial disadvantage.”

This would force game developers who previously relied on Unreal Engine to suddenly have to “(a) start development all over with a new game engine, (b) abandon the iOS and macOS platforms, or cease development entirely.”

Last week, Epic Games announced the Free Fortnite Cup as a farewell for iOS players and its latest shot against Apple. Now that Microsoft has joined forces with Epic Games, Apple will have to think twice to fight against another of the top and leading tech giants.