History of Poplar

Paul McJones, editor
paul@mcjones.org
https://mcjones.org/dustydecks/

Last modified 24 January 2026

Introduction

The goal of this project is to preserve and present primary and secondary source materials (including specifications, source code, manuals, and papers discussing design and implementation) from Poplar, a functional programming language designed at Xerox PARC in the late 1970s. The editor greatly appreciates comments, suggestions, and donations of related materials.

Contents

• Acknowledgments
• Source code
• Documentation
• Papers

Acknowledgments

Thanks to James H. Morris, Jr., the primary designer of Poplar, for giving me permission to post the manual, source code, and paper here and to Ed Satterthwaite for permission to post the 1986 version.

Source code

• James H. Morris and Eric Schmidt. Poplar source code. Written in Mesa, circa 1977-1978. This version uses call-by-value. PDF
• James H. Morris, Eric Schmidt, and Philip Wadler. Poplar source code. Written in Mesa, circa 1977-1979. This version uses lazy evaluation (call-by-need), as described in [Morris, Schmidt, and Wadler 1980]. PDF
• James H. Morris, Eric Schmidt, Phil Wadler. Poplar source code with some modifications for Cedar, circa 1982. [Indigo]<Cedar>Poplar> Online at xeroxparcarchive.computerhistory.org
• James H. Morris, Eric Schmidt, Phil Wadler. Poplar source code with some modifications for Cedar by Ed Satterthwaite, circa April 1986. Online

Poplar programs

• Morris et al. Poplar examples. ex.pl, ex1.pl, ..., ex8.pl. PDF

Documentation

• Jim Morris and Eric Schmidt. Poplar. Draft language manual, 4 October 1978, 38 pages. PDF
• Jim Morris and Eric Schmidt. Poplar Language Manual. 1 November 1978; revised December 1980, version 0.3.
  • [Indigo]<Cedar>Documentation>Poplar.Press!1 PDF at xeroxparcarchive.computerhistory.org
  • [Indigo]<Cedar>Documentation>PoplarIntro.Bravo!1 HTML at xeroxparcarchive.computerhistory.org

Papers and Reports

• James H. Morris, Eric Schmidt, and Philip Wadler. Experience with an applicative string processing language. In Proceedings of the 7th ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages (POPL '80). Association for Computing Machinery, New York, NY, USA, 32–46. ACM Digital Library
• James H. Morris. Real Programming in Functional Languages. In: Functional Programming and its Applications, J. Darlington, P. Henderson and D. Turner (ed.), Cambridge University Press, Cambridge, 1982. Also appeared as: Report CSL-81-11, Palo Alto Research Center, Xerox Corporation, 1 July 1981. PDF at bitsavers.org