XLISP-STAT is a statistical environment based on a dialect of the Lisp
language called XLISP. Originally developed for the Apple Macintosh,
XLISP-STAT is now also available for UNIX workstations using the X11
window system and for use on SUn workstations running suntools. To
facilitate statistical computations standard Lisp functions for
addition, logarithms, etc., have been modified to operate on lists and
arrays of numbers, and a number of basic statistical functions have
been added.  Many of these functions have been written in Lisp, and
additional functions can be added easily by a user.  Several basic
forms of plots, including histograms, scatterplots, rotatable plots
and scatterplot matrices are provided.  These plots support various
forms of interactive highlighting operations and can be linked so
points highlighted in one plot will be highlighted in all linked
plots. Interactions with the plots are controlled by the mouse, menus
and dialog boxes. An object-oriented programming system is used to
allow menus, dialogs, and the response to mouse actions to be
customized.