Help Viewing PostScript and PDF Files What are PDF and PS Files? PS (PostScript) Postscript is a device independent programming language with powerful graphics capabilities.  It was created by Adobe Systems Incorporated in 1985 and has been extended since then.  On most operating systems a postscript file will end in an extension ".ps" or an extension ".eps" for an encapsulated postscript file. PDF (Portable Document Format). PDF files are sometimes called Acrobat files after Adobe's Acrobat reader.  It is closely related to PostScript, but has built-in support for hyperlinks. On most operating systems PDF files end in a ".pdf" extension. Applications for Viewing PostScript and PDF files Adobe's Acrobat reader - for PDF and PS files.  You can download Acrobat Reader from the Adobe web site by following this link.  For Windows or Macintosh. GSview - a program for reading postscript files that has more power than Acrobat.  For Windows only. For Macintosh users who have OS X or higher, the included Preview application can read both PDF and postscript files.