Dr. Giuseppe Primiero is Associate Professor of Logic at the Department of Philosophy, University of Milan (Italy). He is President of the DHST-DLMPST Commission on the History and Philosophy of Computing, Member at Large of the Leadership Committee of the International Association for Computing and Philosophy and since 2016 Secretary General for the Association Computability in Europe. His research areas include logic, philosophy of information and computation.

Liesbeth De Mol is a CNRS researcher based in France. She is the founding president of the DHST/DLMPST Commission for the History and Philosophy of Computing, coundil and steering committee member of the Association for Computability in Europe and principal investigator of the ANR research project PROGRAMme on the history and philosophy of computer programs (2018-2022). Her research focuses on the histoircal and epistemological connections between logic, programming and computing.

Preface.- Part I: Programming without Systems.- Chapter 1. Validity & Correctness before the OS: the case of LEO I and LEO II (Rabia Arif, Elisabetta Mori, Giuseppe Primiero).- Chapter 2. What is an Operating System? A historical investigation (1954-1964) (Maarten Bullynck).- Part II: Formalizing Systems.- Chapter 3. Formal Semantics of ALGOL 60: Four Descriptions in their Historical Context (Troy K. Astarte, Cliff B. Jones).- Chapter 4. Sans-papiers as first-class citizens (Julian Rohrhuber).- Part III: Creating Systems.- Chapter 5. Unix, Plan 9 and the Lurking Smalltalk (Stephen Kell).- Chapter 6. Unix: Building a Development Environment from Scratch (Warren Toomey).- Part IV: Evaluating Systems.- Chapter 7. Ethical Operating Systems (Naveen Sundar Govindarajulu, Selmer Bringsjord, Atriya Sen, Jean-Claude Paquin, Kevin O'Neill).- Chapter 8. From Sovereign Operating Systems to the Sovereign Digital Chain (Gael Duval).- Chapter 9. Elegance in Software (Robin K. Hill).