Detours is a software package for re-routing Win32 APIs underneath applications. For almost twenty years, has been licensed by hundreds of ISVs and used by nearly every product team at Microsoft. What’s New? Detours 4.0.1 is now open source under the MIT license. Detours is on GitHub at https://github.com/Microsoft/Detours (opens in new tab). The source code is identical to Build 343 of Detours 3.