Software programs are often made to run on systems that are completely
different from the system in which the program is coded or developed.
This process of adapting software across systems is known as porting.
You might need to port software for any one of several reasons.
Perhaps your end users want to use the software in a new environment,
such as a different version of UNIX®, or perhaps your developers are
integrating their own code into the software to optimize it for your
organization's platform.
read full article http://www.ibm.com/developerworks/aix/library/au-porting/
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