http://www.research.att.com/sw/tools/graphviz/ http://home.so-net.net.tw/oodtsen/wingraphviz/

http://www.gnuplot.info/ http://ayapin.film.s.dendai.ac.jp/~matuda/Gnuplot/gnuplot.html http://t16web.lanl.gov/Kawano/gnuplot/ http://adlib.rsch.tuis.ac.jp/~akira/zemi/gnuplot/wgnupl.htm