2.3 Why shouldn’t we Port? Portability is not desirable in all situations. Here are some reasons we may not want to invest in portability: Sometimes even a small extra cost or delay in getting the product out the door is not considered tolerable. Sometimes even a small reduction in performance or storage efficiency cannot be accepted. Sometimes a software unit is so tightly bound to a specialized environment that a change is extremely unlikely. Sometimes source files or documentation are unavailable. This maybe because developers or vendors are protective of intellectual property rights.