The PSTricks macros cannot be used (directly) with pdfTeX, since PSTricks uses PostScript arithmetic, which isn't part of PDF. This package circumvents this limitation so that the extensive facilities offered by the powerful PSTricks package can be made use of in a pdfTeX document. This is done using the shell escape function available in current TeX implementations. The package may also be used in support of other PostScript-output-only packages, such as PSfrag.