# Foreword

In 1964 the National Institute of Standards and Technology^{1}^{1}Then known as
the National Bureau of Standards. published the *Handbook of
Mathematical Functions with Formulas, Graphs, and Mathematical Tables*, edited by
Milton Abramowitz and Irene A. Stegun. That 1046-page tome proved to be an invaluable
reference for the many scientists and engineers who use the special functions of applied
mathematics in their day-to-day work, so much so that it became the most widely
distributed and most highly cited NIST
publication in the first 100 years of the
institution’s existence.^{2}^{2}D. R. Lide (ed.), *A Century of Excellence in Measurement, Standards, and Technology*,
CRC Press, 2001.
The success of the original handbook, widely referred to as
“Abramowitz and Stegun” (“A&S”), derived not only from the fact that it provided
critically useful scientific data in a highly accessible format, but also because it served to
standardize definitions and notations for special functions. The provision of standard
reference data of this type is a core function of NIST.

Much has changed in the years since A&S was published. Certainly,
advances in applied mathematics have continued unabated. However, we have also seen
the birth of a new age of computing technology, which has not only changed how we
utilize special functions, but also how we communicate technical information. The
document you are now holding, or the Web page you are now reading, represents an
effort to extend the legacy of A&S well into the 21st century. The new printed volume,
the *NIST Handbook of Mathematical Functions*, serves a similar function as the original
A&S, though it is heavily updated and extended. The online version, the *NIST Digital
Library of Mathematical Functions (DLMF)*, presents the same technical information
along with extensions and innovative interactive features consistent with the new
medium. The DLMF may well serve as a model for the effective presentation of
highly mathematical reference material on the Web.

The production of these new resources has been a very complex undertaking some 10 years in the making. This could not have been done without the cooperation of many mathematicians, information technologists, and physical scientists both within NIST and externally. Their unfailing dedication is acknowledged deeply and gratefully. Particular attention is called to the generous support of the National Science Foundation, which made possible the participation of experts from academia and research institutes worldwide.

*Dr. Patrick D. Gallagher*

*Director, NIST*

November 20, 2009

Gaithersburg, Maryland