This is the FileSystem used by OperatingSystems based on MicrosoftCorporation's WindowsNT. It fixes many of the Nasty Nasty problems of FAT32: it has proper long file name support, permissions, journalling, and better data internal structures (zones of data with information about that zone being stored at the beginning or end, as most other FileSystems), and is less prone to fragmentation. It also has advanced features like alternative streams for files and transparent per-file compression and encryption.
Linux can usually read NTFS Partitions, and it can write to them sometimes without completely screwing them up. This situation appears to have improved as many developers seem to be working on the NTFS driver. Check out the Linux NTFS Project; IanMcDonald's experience is that this driver sometimes refuses to write or delete but still works better than the LinuxKernel drivers.