Source : Free On-Line Dictionary of Computing

lock-in
     
         When an existing standard becomes almost impossible
        to supersede because of the cost or logistical difficulties
        involved in convincing all its users to switch something
        different and, typically, {incompatible}.
     
        The common implication is that the existing standard is
        notably inferior to other comparable standards developed
        before or since.
     
        Things which have been accused of benefiting from lock-in in
        the absence of being truly worthwhile include: the {QWERTY}
        keyboard; any well-known {operating system} or programming
        language you don't like (e.g., see "{Unix conspiracy}"); every
        product ever made by {Microsoft Corporation}; and most
        currently deployed formats for transmitting or storing data of
        any kind (especially the {Internet Protocol}, 7-bit (or even
        8-bit) {character sets}, analog video or audio broadcast
        formats and nearly any file format).
     
        Because of {network effects} outside of just computer
        networks, {Real World} examples of lock-in include the current
        spelling conventions for writing English (or French, Japanese,
        Hebrew, Arabic, etc.); the design of American money; the
        imperial (feet, inches, ounces, etc.) system of measurement;
        and the various and anachronistic aspects of the internal
        organisation of any government (e.g., the American Electoral
        College).
     
        (1998-01-15)