The battle between Apple Inc. AAPL 1.20% and the creator of “Fortnite” is doing more than just fraying a nearly decadelong relationship. It is also prompting other tech heavyweights such as Microsoft Corp. to step in, as the feud has escalated to a point where it could upend business at makers of videogames, Hollywood productions and virtual-reality simulations.
Apple, the world’s most valuable company, earlier this month threatened to pull Epic Games Inc.’s developer credentials—which are required to release software on Apple devices—after Epic introduced a way to buy virtual goods within the popular videogame that skirts the tech giant’s 30% commission on in-app purchases. The restriction would leave Epic unable to update “Fortnite” on iPhones and iPads—as well as its Unreal Engine, a software suite used to build mobile games among other apps and to create complex video effects and animations.
Microsoft has placed its support behind Epic’s motion, saying in a court filing Sunday that it uses Unreal’s tools for the mobile game “Forza Street” and that restrictions on Epic could hamper its game-development business.
Microsoft has been vocal in recent months in challenging how app stores operate. Earlier this month, Microsoft criticized Apple after the company declined to put its new game-streaming app in the App Store. In June, Microsoft President Brad Smith said during a Politico webinar that app marketplaces “have created higher walls and far more formidable gates to access to other applications than anything that existed in the industry 20 years ago.” Mr. Smith said in contrast, if a company wants to provide its apps on Windows, it can go directly to a personal-computer manufacturer or use the web to reach a consumer.