SHELL: Global Tool for Calling and Chaining Procedures in the System (1965) [pdf]
people.csail.mit.eduSee the Multics History Project:
https://people.csail.mit.edu/saltzer/Multics/Multics-Documen...
More context here, https://multicians.org/shell.html by Louis Pouzin himself, a not-so-well known father of the Internet.