I first heard about LISP 2 around 1971, from a 1966 conference paper included in the reading for a U.C. Berkeley seminar on advanced programming languages. The goal of LISP 2 was to combine the strengths of numerically-oriented languages such as ALGOL and FORTRAN with the symbolic capabilities of LISP. The paper described the language and its implementation at some length, but by 1971 it was pretty clear that LISP 2 had not caught on; instead, the original LISP 1.5 had spawned a variety of dialects such as BBN-LISP, MACLISP, and Stanford LISP 1.6.
In 2005 I began a project to archive LISP history and kept encountering people who’d been involved with LISP 2, including Paul Abrahams, Jeff Barnett, Lowell Hawkinson, Michael Levin, Clark Weissman, Fred Blair, Warren Teitelman, and Danny Bobrow. By 2010 I had been able to scan LISP 2 documents and source code belonging to Barnett, Herbert Stoyan, and Clark Weissman. In 2012, after writing about Hawkinson and others in an extended blog post “Harold V. McIntosh and his students: Lisp escapes MIT,” I decided to try to tell the story of the LISP 2 project, where so many interesting people’s paths had crossed. My sources included original project documents as well as telephone and email interviews with participants, and several participants were kind enough to provide feedback on multiple drafts. I let the article sit in limbo for five years, but last year after I published another anecdote in the Annals, editor Dave Walden encouraged me to submit this one.
On December 28, 2017, as the article was about to go to press, Lowell Hawkinson died suddenly from an accident.