mz

from The Free On-line Dictionary of Computing (8 July 2008)

MZ

   <standard, file format> The file signature of an {MS-DOS}
   executable (.{EXE}) file (0x4d 5a), always the first two
   {bytes} of the file.  It was reportedly invented by, and named
   after, a {Microsoft} programmer, Mark Zbikowski.

   In {Unix} systems, the string MZ is the {magic number} that
   identifies an MS-DOS EXE file.

   (2003-06-10)

from The Free On-line Dictionary of Computing (8 July 2008)

mz

   <networking> The {country code} for Mozambique.

   (1999-01-27)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

MZ
       Mark Zbikowski (MS-DOS, MCB)