Postscript

Postscript is a programming language. It was developed by Adobe, in 1984. It is a standard used by many computer printers. There are three different versions of it, Postscript Level 1, Level 2, and Level 3.

The Portable Document Format is another standard, also from Adobe. It is better adapted to printing. Many things computer languages have, have been dropped to develop PDF.

"Hello world"

And finally, a Hello World program, the customary way to show a small example of a complete program in a given language, might look like this in Postscript:

%!PS
/Courier findfont
20 scalefont
setfont
72 500 moveto
(Hello world!) show
showpage

or if the output device has a console

%!PS
(Hello world!) =