Rob Maier wrote the libplot/libplotter library and the graphics programs graph, plot, tek2plot, and plotfont, 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 at least 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 is based on the Tektronix parser written by in the mid-1980's by Edward Moy (then of Berkeley, later at Xerox, and now at Apple). This is the parser used by `xterm', in the X11 distribution. ode was written by Nick Tufillaro in 1978-1994, and has been somewhat modified and extended so as to merge it into the package. 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 as part of groff, i.e. GNU troff. A libplot driver was added, to turn it into pic2plot. Rob wrote the texinfo manual (the chapter on ode draws heavily on Nick's original ode documentation, which dates 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.