The Hewlett Packard Corporation developed HP PCL in 1984 for its first laser jet printer. PCL’s purpose was to control printer features across a wide variety of print devices. PCL commands are compact escape sequence codes embedded in the print job data stream, explains Hewlett Packard's manual on printer language history. PCL has continued to evolve since its introduction; today HP PCL is the most widely-used industry standard printer command language in the world. Each PCL update included all of the previous PCL version functionalities, so that backwards compatibility was ensured.
When the HP PCL5 solution was introduced, it included HP GL/2, the control language that supports HP’s CAD plotters and vector graphics support. HP PCL5, working with HP GL/2, readily supports fonts of any spacing, scale and design; this includes mono-spaced and proportionally scaled fonts, rotated, scalable, filled/shadowed/mirrored, downloaded as well as downloaded predesigned forms and overlays. This flexibility is very important when dealing with today’s numerous and complex bar codes.
Virtually any system can communicate with a PCL printer, making it the de facto language solution for any printer using any print technology - including thermal bar code label printers.