This version of pst-tvz uses the xkeyval package, the extended version of keyval. Save the files pst-tvz.sty|.tex| in a directory, which is part of your local TeX tree. Then do not forget to run texhash to update this tree if these packages are new to your TeX distribution. For more information see the documentation of your LaTeX distribution on installing packages into your LaTeX distribution or the TeX Frequently Asked Questions: (http://www.tex.ac.uk/cgi-bin/texfaq2html?label=instpackages). pst-tvz needs pstricks and pst-node which should be part of your local TeX installation, otherwise get it from a CTAN server, f.ex. http://mirror.ctan.org/graphics/pstricks/