The package was originally written for Unix
and this is still the best environment to run it.
Unifpack has been succesfully ported and tested on HP-7XX (HPUX 8.07 ),
Apollo workstations (Domain/OS SR10.4 ) and Linux (SLS 0.99pl10 ). It has been ported to
Sun's and Aviion's, but that was long ago and may not work now.
Unifpack is written in ANSI/C, so an ANSI/C compiler is needed this means more than just prototypes, for instance your C preprocessor has to accept the ## directive, gcc works OK for me.
The presentations are read using yacc and lex, the interface use them too to read the command line, bison and flex work too.
Your *IX should distinguish more that six chars on global symbols, if possible something like 10K chars (just kidding), this is one of the ``C Commandments'' I'm afraid I will never follow.
The Makefile's provided use the include directive, and some sed scripts have comments, if you run into problems because of this you can use the GNU tools instead of the ones provided with you OS, if you prefer, you can edit out the comments and manually include the needed parts in the Makefile's.
Unifpack implements a very simple device driver mechanism to produce its
graphics,
currently there are drivers for X11 (using Xlib), SRGP ,
and Fig ,
if you want to see any graphics you'll
need some of this softwares,
I expect to use graphics from GNU someday,
but until then X11 and Fig (both) are probably the best choices.
In case you don't know Fig is a graphics file protocol
designed by
Supoj Sutanthavibul;
there is a conversion tool called
transfig
by Micah Beck
that let you transform from Fig to several graphics formats,
including Encapsulated PostScript, EEPIC,
(although limitations make some pictures look horrible),
and several others, so you can print your polygons or include them in
a 
or document.