Which file system was designed to replace the FAT file system?

The file system designed to replace the FAT (File Allocation Table) file system is NTFS (New Technology File System). NTFS was introduced with Windows NT and has since become a standard file system for Microsoft Windows operating systems. Unlike FAT, NTFS supports advanced features such as file permissions for security, encryption, disk quotas for managing disk space usage, and improved file recovery options.

NTFS also includes support for larger file sizes and volumes than what FAT can manage. It provides better performance and reliability, especially in environments that require handling large amounts of data or where data integrity is paramount, such as enterprise and server environments.

The other file systems listed, while important in their own contexts, do not serve as direct replacements for FAT in the way that NTFS does. For example, ZFS is mainly used in Unix-like systems, EXT is commonly found in Linux operating systems, and UFS is also primarily associated with BSD Unix systems. None of these were specifically designed to replace FAT in the Windows environment as NTFS was.