Do you often work with PDF and PostScript files? if you do, then this Ghostscript application will become essential to you.
It is a collection of utilities that let you print documents in PDF format, interpret the PostScript language, transform a PDF to a traced format, allow printers that have PostScript implemented, etc.
Additionally, with GhostScript you can transform a file in PostScript language to PDF and vice versa. In summary, an absolutely essential tool for working with these types of document.