reverse engineering

    The process of analysing an existing
   system to identify its components and their interrelationships
   and create representations of the system in another form or at
   a higher level of abstraction.  Reverse engineering is usually
   undertaken in order to redesign the system for better
   maintainability or to produce a copy of a system without
   access to the design from which it was originally produced.

   For example, one might take the executable code of a
   computer program, run it to study how it behaved with
   different input and then attempt to write a program oneself
   which behaved identically (or better).  An integrated
   circuit might also be reverse engineered by an unscrupulous
   company wishing to make unlicensed copies of a popular chip.

   (1995-10-06)