Every source I can find says that NTFS is proprietary Microsoft code, but I can still find the specifications for it and open source drivers, like NTFS-3G, made by Tuxera. I can't find any record of Microsoft releasing the specifications, working with Tuxera on NTFS, or trying to fight Tuxera either.
I am confused by this because it contradicts my understand of proprietary standards. Is NTFS-3G a violation of the license for NTFS? And if so, has Microsoft done anything about it?