a) Please install libgd, libcgic and libproj as documented.

b) Look at "init.h"... Install the data files earth.rez, karte.html, 
gelb_lonlat.txt and rot_lonlat.txt on a location of your webserver where you
can read them with a cgi program.  

c) The file welt.png should be accessible for the webserver itself. Place it
into a tmp directory the cgi has write permission for. There you can store
the calculated maps of karte_cgi.    

d) help.html should find a place within your webserver tree.

e) Edit "karte.html": The "action" method should point to karte_cgi on your
webserver and "image src" to welt.png. Dont forget the link to the help page.

f) Adapt "init.h" to your needs.

g) make

h) Copy karte_cgi into your cgi-directory

i) enjoy