Hewlett-Packard Graphics Language (.hpgl)
The HPGL file extension, short for Hewlett-Packard Graphics Language, is a file format and printer control language developed by Hewlett-Packard in 1977 for use with their plotter printers, starting with the HP-9872. HPGL files contain commands that instruct plotters to draw images using lines rather than dots, making them essential in CAD applications and technical drawings. The language uses a series of two-letter codes followed by parameters to control the plotter's actions, such as moving the pen or drawing shapes.