Unix Magic Poster Annotations
This is the UNIX Magic Poster, originally created by Gary Overacre in the mid-1980s and published by UniTech Software.
unix
9FRONT.ORG
Plan 9 is a research operating system from the same group who created UNIX
Command Line Interface Guidelines
An open-source guide to help you write better command-line programs, taking traditional UNIX principles and updating them for the modern day.