Microsoft is siding with Epic Games in the legal battle against Apple's App Store "tax," arguing in a new legal brief that Apple has "stymied" Microsoft's planned launch of an Xbox game store.A year ago,

The court ruling makes it possible for Microsoft to now launch its Xbox mobile store, but it’s clear that the software giant also wants to ensure Apple’s appeal against the ruling isn’t successful. If Microsoft did launch its Xbox mobile store and then Apple won a temporary stay, it may have to pull that store pending the appeal process.

Microsoft pinpoints Apple and its old App Store policies as the main culprits that prevented the launch of a mobile-centric Xbox game and app store.