NDOS is a "DOS shell" (a program that gives you access to DOS functions and commands), but it's unlike most DOS shells on the market. Virtually all of these other shells are designed to isolate the novice user from the DOS command line. NDOS, on the other hand, is intended to make DOS easier to use and to make you more productive while working at the command line. It provides enhancements to most of the DOS commands, as well as more than 40 new commands. These improvements make NDOS a much richer and more powerful working environment than COMMAND.COM, without sacrificing the compatibility, flexibility and control you get from working at the command line.
NDOS is a complete replacement for COMMAND.COM, the command processor provided with DOS (either MS-DOS or PC-DOS). NDOS is compatible with DOS versions 2.1 and above and the OS/2 DOS compatibility box, adding many enhancements to your DOS prompt, including: NDOS requires 3K of your precious RAM for its resident portion (less than 1K with UMBs), and can use EMS, XMS, or disk for swapping its transient portion.