Shellscripts and Commands: practical development method from large-scale academic research to mission-critical business system Universal Shell Programming Liboratory has developed many kinds of mission-critical business systems for many companies based on their own unique and innovative development method for SI and big-data processing. The main idea of that might be too simple to believe in: text files, commands and shellscripts. You can convert almost any kind of your data into text. Then the development method tells you how to organize your data in what directories. As a result, it realizes fast processing and easy coding. This method is applicable in many areas, from as small tools to larg-scale data processing. I describe their development method in a tangible way using Open usp Tukubai and FreeBSD.