This is why the UNIX way, where every program does only one thing and does it well, is so powerful. You don't need to know how it works to use it. And if it re

This is why the UNIX way, where every program does only one thing and does it well, is so powerful. You don't need to know how it works to use it. And if it really needs changing you can make a new executable with a new version number in its name. That way legacy code can continue to call on the old still functioning version while other peaces of code call on the new version.