PCL stands for Printer Command Language. The
language is the native language of many HP
printers. Some basic PCL documentation can be
found at http://www.hp.com/cposupport/printers/support_doc/bpl02705.html
Windows printer drivers that talk to HP
printers will almost always use PCL, unless the
printer supports postscript, which is rarely the
case for personal or home printers. In the UNIX
world, where printers are practically expected to
speak postscript, you need to set up a filter to
convert the postscript into PCL. Ghostscript is
usually the program used to do the actual
conversion.