The package allows the user to use the computer algebra system XCAS to generate tables of signs and of variations (the actual plotting of the tables uses the MetaPost macro package "tableauVariation.mp" : http://frederic.mazoit.free.fr/LaTeX_metapost/tableauVariations/ . The tablor package requires that shell escape be enabled. For instance : \begin{TV} TV([-10,+infinity],[-1,1],"g","t",x^2/(x^2-1),1,\tv) \end{TV} draws table of variations of x->x^2/(x^2-1). You can download XCAS here: http://www-fourier.ujf-grenoble.fr/%7Eparisse/giac.html The non-french users need to comment out every " \usepackage[upright]{fourier} " Just put tablor.sty and tablor.cfg into /texmf/tex/latex/tablor/