Makes PTS-DOS 2000: network support, file manager, archiver, internal boot virus protection, graphical web browser; email, telnet, FTP clients; many utilities, some for embedded system development. http://www.phystechsoft.com/ptsdos/
Makes PC DOS 2000; was one of the two original DOSes for the IBM PC. Now year 2000 compliant, and updated for a new century. Preserve your investment in DOS applications. http://www-3.ibm.com/software/os/dos/
Reduced Memory Footprint; goals: match functions of MS-DOS 6.22, IBM PC DOS 7.00, DR-DOS 7 subset. Written mainly in 2 free C compilers and assembler, most parts are smaller uncompressed than compressed parts of MS, IBM, DR. [Open Source, BSD] http://sourceforge.net/projects/rmfdos/