The Software Development Kit (SDK) for the Xbox One has reportedly been leaked. A group called H4LT has apparently leaked the SDK, announcing the leak on their Twitter account. The group says that this leak is aimed at getting the console modding community to build momentum for potential homebrew apps on the Xbox One. H4LT also appears to have leaked the documentation for the SDK.
H4LT has said that they plan to leak more software in the future, but are not announcing what that software is at this time.
Source: The Tech Game