Daniel Weinreb's Road to Lisp

Daniel Weinreb: Creating Common Lisp and Lisp machines

When did you first try Lisp seriously, and which Lisp family member was it?

I first started using Lisp in 1976, using MacLisp for the PDP-10 under ITS. Very soon afterwards I began using the nascent Lisp machine dialect.

What led you to try Lisp?

I was hired at the MIT Artificial Intelligence Lab to work on the new Lisp machine project. My first assignment was to learn Lisp.

What other languages have you been using most?

Back then, I had primarly used BASIC and PDP-10 assembly language, but I had familiarity with ALGOL and PL/I.

How far have you gotten in your study of Lisp?

Pretty far. I am one of the designers of Common Lisp.

What do you think of Lisp so far?

Lisp is pretty much my "native" computer programming language. From 1976 to about 1990, I'd describe myself as a total Lisp enthusiast, feeling that Lisp was better than every other language in every way. Now that I have spent time programming in C++ and Java, I more appreciate the virtues of Java, particularly the value of static typing, and I have learned more about the benefits of other languages. However, Lisp is still and will always be my favorite language.

I am currently at ITA Software, working with a very large team of excellent software engineers, building a high-availability, high-performance, full-functionality airline reservation system (initially for Air Canada). The business tier (the "core") consists of about 1/2 million lines of Common Lisp. We are the largest (about 65) single team in the world developing in Common Lisp.

Switch Date 1970s