Rob Maier <rsm@math.arizona.edu> wrote the libplot/libplotter library and
the graphics programs graph, plot, tek2plot, plotfont, and hersheydemo,
beginning in 1995.  The old `GNU graphics' package (written by Rich Murphey
in 1989-1991) served as a starting point, but the plotutils package is over
an order of magnitude larger.  Probably none of the code from the earlier
package remains in libplot/libplotter or the graphics programs.

spline and double were originally written by Rich.  They have been extended
by Rob, but some of Rich's code is still present.

tek2plot was based by Rob on the Tektronix parser written in the mid-1980's
by Edward Moy (then of Berkeley, later at Xerox, and as of last report at
Apple).  This is the parser used by the standard terminal emulator `xterm',
when it is in Tektronix mode.  The idea of tek2plot originated with Rich,
though.  (The old `GNU graphics' package contained a tek2plot.)

ode was written by Nick Tufillaro <nbt@reed.edu> in 1978-1994, and was
somewhat modified and extended by Rob so as to merge it into the package.
The file ode/specfun.c, which provide gnuplot-style special function
support to ode, was written by Rob in 2009, replacing a file (distributed
in earlier releases) that had copyright problems.

Most of the code in pic2plot (the scanner and parser code, in particular)
is taken from gpic, i.e. GNU pic.  gpic was written in 1989-1992 by 
James J. Clark <jjc@jclark.com> as part of groff, i.e. GNU troff.
A libplot driver was added by Rob, to turn it into pic2plot.

Rob wrote the texinfo manual, but the chapter on ode draws heavily on
Nick's original ode documentation, dating in part to the late 1970s.

The libxmi scan-conversion library was extracted by Rob from source files
in the X11 distribution, with modifications.  The source files were written
in the mid-to-late 1980's by Brian Kelleher, Joel McCormack, Todd Newman,
Keith Packard, Bob Scheifler and Ken Whaley, who worked for Digital
Equipment Corp., MIT, and/or the X Consortium.  Their contributions are
copyright 1985-89 by the X Consortium.  See ./libxmi/README-X for X
Consortium permission notices.