Here's how to make *everything* conveniently on a unix-like system.

The makefile is built by running the file makefile.m4 through the m4 macro
processor with an appropriate system macro defined.  This allows multiple
configurations to be easily supported, similar to 'imake'.  Macros for system
type include: HPUX, SUNOS, AIX, UNICOS, SYSV, DGUX, LINUX, NEXT, ULTRIX, BSD,
AMIGA.  One of these *must* be specified, or if necessary you can add system
specific defines analogous to the existing ones.  There are also the macros
DOUBLE (for double precision), DEBUG (debugging), PROFILE (for enabling
profiling code, if supported by the compiler) and OPT (optimization).  Please
look at the comments in makefile.m4 for more info.

You must ensure that the appropriate system header files can be found by the
generated makefile.  This is occasionally a problem for X11 header files,
e.g. they might be in /usr/include/X11, /usr/include/X11R4/X11,
/usr/include/X11R5/X11, etc.  This can usually be solved by setting the
appropriate environmental variables.  For example, under HPUX 9.01 I have the
following set in my .login:

setenv CCOPTS	"-I/usr/include/X11R5"
setenv CXXOPTS	"-I/usr/include/X11R5"
setenv LDOPTS	"-L/usr/lib/X11R5 -L/usr/lib/Motif1.1"


To build the makefile, starting from the plplot directory:

	% cd tmp
	% cp ../sys/unix/makefile.m4 .
	% m4 -D<sys> <makefile.m4 >makefile

where <sys> is the appropriate system name.
Then, while in the tmp directory:

	% make links

sets up links to all the files you will ever need.

	% make

makes the main library, for the default precision (probably single on a
workstation).  Finally, to make a demo,

	% make x01c

for the first C demo, or

	% make x01f

for the first Fortran demo.

The easiest way to install the library is to type "make install".  This
assumes there exists a directory /usr/local/plplot and
/usr/local/plplot/include that you can write into.  I've found it is not
difficult to get the system administrator to give you ownership of such
a directory on systems that you use.  At the sysadm's option, softlinks
can be made to /usr/local/lib, /usr/local/bin, /usr/local/include, or
whatever, leaving you free to install new plplot versions as they become
available.

The font files will be put into /usr/local/plplot by "make install", but
there are actually several places where PLPLOT looks for them.  The default
search path is:

       current directory
       $(HOME)/lib/
       $(PLFONTS)
       PLFONTDEV1      (/usr/local/lib/)
       PLFONTDEV2      (/usr/local/lib/plplot/
       PLFONTDEV3      (/usr/local/plplot/)

You probably should also print & read the TeX documentation on the Unix
installation.

Finally, there's a bunch of shell scripts in the plplot directory to help
you archive all the source files using 'zoo', 'tar', or 'zip'.  
