Ghostscript

• An interpreter for Portable Document Format (PDF) files, with the same abilities;
  
• The ability to convert PostScript language files to PDF (with some limitations) and vice versa; and
  
• A set of C procedures (the Ghostscript library) that implement the graphics capabilities that appear as primitive operations in the PostScript language.
  

GSview is a graphical interface for Ghostscript. Ghostscript is an interpreter for the PostScript page description language used by laser printers. For documents following the Adobe PostScript Document Structuring Conventions, GSview allows selected pages to be viewed or printed. GSview requires Ghostscript. GSview is available for Windows, OS/2 and Linux.