What is a good software? A software that does everything we expect? A one that has an attractive user interface? A one with “good” documentation? The definition of good software is context-specific, and good software for one person may not be the same for another. Everyone has their metrics and its view of a good software.
But, what about useful software? We can get the definition of a useful software:
“A useful software is the software that can be used for a practical purpose.”
It may not be the best solution, it may not be optimized, it may not look good, but it solves the problem facing us now. It accomplishes the practical purpose it is built for.
For a software engineer, it’s generally complex to build useful software. We cannot predict many aspects of software up-front, but, we can design our software to be adaptable and easy to change and to enhance. So, we can make further changes and improvements easily in the future to meet more specifications.
Unix and Unix-like systems have been built with great design philosophies in mind, and they are still useful nowadays.