1. While pdfLaTeX has a number of nice features, its primary shortcoming relative to standard LaTeX+dvips is that it is unable to read ordinary Encapsulated PostScript (EPS) files, the most common graphics format in the LaTeX world. purifyeps converts EPS files into a "purified" form that can be read by *both* LaTeX+dvips and pdfLaTeX. The trick is that the standard LaTeX2e graphics packages can parse MetaPost-produced EPS directly. Hence, purifyeps need only convert an arbitrary EPS file into the same stylized format that MetaPost outputs. (from http://computing.ee.ethz.ch/sepp/purifyeps-1.0-to.html)

2. purifyeps - make an Encapsulated PostScript file work with both dvips and pdflatex. (from the manual pages)