Here is a summary of the early history of the GNU plotting utilities.

Versions of `graph' and the plot filters existed in many early releases of
Unix, going at least as far back as the Version 7 distribution from Bell
Labs.  Supported devices in those days (c. 1980) included Versatec and
Varian 200dpi electrostatic printer/plotters, Tektronix storage scopes, and
early graphics terminals.

Rich Murphey <rich@lamprey.utmb.edu> wrote the first GNU versions of graph,
the plot and tek2plot filters, double and spline, and the documentation.
Richard Stallman <rms@gnu.ai.mit.edu> further directed development of the
programs and provided editorial support for the documentation.  John
Interrante <interran@uluru.stanford.edu> generously provided the Postscript
prologue now included in libplotps, and helpful comments.  The
distribution, as it stood in 1991, was distributed under the name `GNU
graphics'.

In 1995 Robert Maier <rsm@math.arizona.edu> took over development of the
package, and wrote the current, maximally device-independent, standalone
versions of libplot.  He also rewrote `graph' from scratch, turning it into
a real-time filter that would use the new libraries.  The idea of including
scalable font support in libplot came from `axis', a much-hacked version of
the Unix `graph' program which is popular in the physics community.  `axis'
uses the character set of the Unified Graphics System [UGS], a system that
was developed at the SLAC Computation Research Group by Robert C. Beach.
The UGS character set includes many scalable Hershey glyphs and marker
symbols (see ftp://ftp.slac.stanford.edu/software/ugs77/ ), so Robert Maier
added the UGS marker symbols to `libplot', and then the entire library of
Hershey glyphs.

The Hershey glyphs (designed c. 1967 by Allen Hershey, who deserves a vote
of thanks!) were assembled mostly from Pete Holzmann's distribution to
Usenet (in vol. 4 of mod.sources).  Additional `extended Hershey' vector
glyphs were taken from the freeware distribution of Thomas Wolff
<wolff@inf.fu-berlin.de>, which is incorporated in Ghostscript, and a set
of 13 Hershey fonts was constructed.  After the Hershey fonts were added,
support for the 35 standard Postscript fonts was added as well, to
libplotfig, libplotps, and libplotX.  Work on this had begun with Rich
Murphey's work on `libps' (the ancestor of libplotps).  At that point, the
support for drawing text strings became completely device-independent.

Robert also rewrote `spline', adding support for periodicity and tension,
and added support for being a real-time filter (using cubic Bessel
interpolation).

ode was originally developed by Nick Tufillaro <nbt@reed.edu> on a sequence
of platforms that extended back to a PDP-11 running Version 4 Unix.  In
1997 Robert modified Nick's 1994 version to agree with GNU conventions on
coding and command-line parsing, and extended it to support the full set of
special functions supported by gnuplot.  Nick kindly agreed to the
inclusion of the modified version in the package.

After all the above work, version 1.1 of the plotutils was released in 7/97.
For later changes to the package, see the file NEWS.
