Windows NT has a kernel mutex type called a "mutant" that was added for compatibility with OS/2's mutex (back when the NT team was still pretending to be building a new OS/2 kernel). Dave Cutler thought the OS/2 mutex semantics were "brain-damaged" and called NT's version "mutant". If an OS/2 thread exited while holding a mutex, the mutex would remain inaccessible forever.

https://blogs.msdn.microsoft.com/larryosterman/2004/09/24/cl...