The Unix philosophy emphasizes building simple, short, clear, modular, and extensible code that can be easily maintained and repurposed by developers other than its creators. The Unix philosophy favors composability as opposed to monolithic design.

Later summarized by Peter H. Salus in A Quarter-Century of Unix (1994):[1] This is the Unix philosophy:

  • Write programs that do one thing and do it well.
  • Write programs to work together.
  • Write programs to handle text streams, because that is a universal interface.

Ken Thompson and Dennis Ritchie, key proponents of the Unix philosophy