Nit: gnuplot not GNUPlot
Any reference to GNUplot is incorrect. The real name of the program is "gnuplot". You see people use "gnuplot" quite a bit because many of us have an aversion to starting a sentence with a lower case letter, even in the case of proper nouns and titles. gnuplot is not related to the GNU project or the FSF in any but the most peripheral sense. Our software was designed completely independently and the name "gnuplot" was actually a compromise. I wanted to call it "llamaplot" and Colin wanted to call it "nplot." We agreed that "newplot" was acceptable but, we then discovered that there was an absolutely ghastly pascal program of that name that the Computer Science Dept. occasionally used. I decided that "gnuplot" would make a nice pun and after a fashion Colin agreed.
It's a very nice tool. Formatting isn't perfect, especially when moving graphs into MS Word, and it does have some quirks, but it works very well for me. YMMV. :-)
Cheers,
Scott.