Xprint
Xprint is an extended printing system that allows X11 programs to use devices such as printers or faxes .
It also allows documents to be laid out in PostScript , PDF , PCL etc. formats . This works by creating a virtual printer, which in turn, instead of sending the printout to the printer , sends it to a program which then creates the printout as a document .
Xprint is developed under the GPL. It is now considered out of date.