Source : Free On-Line Dictionary of Computing

Application Binary Interface
     
         (ABI) The interface by which an {application
        program} gains access to {operating system} and other
        services.  It should be possible to run the same compiled
        {binary} applications on any system with the right ABI.
     
        Examples are {88open}'s {Binary Compatibility Standard}, the
        {PowerOpen Environment} and {Windows sockets}.
     
        (1994-11-08)