A prodigy, L Peter Deutsch started programming in the late '50s, at age 11, when his father brought home a memo about the programming of design calculations for the Cambridge Electron Accelerator at Harvard. He was soon hanging out at MIT, implementing Lisp on a PDP-1, and hacking on and improving code written by MIT hackers nearly twice his age.

As a sophomore at UC Berkeley, he got involved with Project Genie, one of the first minicomputer-based timesharing systems, writing most of the operating system's kernel. (Ken Thompson, inventor of Unix and the subject of Chapter 12, would also work on the project while a grad student at Berkeley, influencing his later work on Unix.) After participating in a failed attempt to commercialize the Project Genie system, Deutsch moved to Xerox PARC, where he worked on the Interlisp system and on the Smalltalk virtual machine, helping to invent the technique of just-in-time compilation.