In Ridley Scott's film ``Blade Runner'' replicants are humanoid robots.
Rachael and Ron Batty are replicants of the same series; Racheal is a
caring woman who does not know she is a replicant; Batty, on the other
hand, is a slave, who kills in an attempt to revert a failsafe system
implanted in them that restricts the life-span to four years. Both are
clones of the same series, yet both develop into very different
individuals, and both will die after their four years are completed.

This position paper focuses on the code migration between different
software applications or systems and the subsequent evolution of code
copies. A piece of code---often an entire file or function---can be
copied from one system to another for many different reasons,
including adding features already implemented in the other system, the
need to fix a bug relying on a known and robust implementation, or the
migration of a developer from one project to another.