\begin{comment}
Each symbol is pushed onto a stack as it is read. Special symbols called ``operators'' can act upon this stack and/or the output device. An internal ``graphics state'' stack can be constructed to store styling information (such as colour, line thickness, the current cursor position). It is possible for the language to define new operators.\end{comment}
PostScript was and is still widely used in printing of documents onto paper; many printers execute postscript directly, and newer formats including PDF must still be converted into PostScript by printer drivers\cite{pdfref17, cheng2002portable}.
\begin{comment}
Each symbol is pushed onto a stack as it is read. Special symbols called ``operators'' can act upon this stack and/or the output device. An internal ``graphics state'' stack can be constructed to store styling information (such as colour, line thickness, the current cursor position). It is possible for the language to define new operators.\end{comment}
PostScript was and is still widely used in printing of documents onto paper; many printers execute postscript directly, and newer formats including PDF must still be converted into PostScript by printer drivers\cite{pdfref17, cheng2002portable}.