HPGL (.hpgl)

HPGL (Hewlett-Packard Graphics Language) is a vector-based plotter control language developed by Hewlett-Packard in the late 1970s. It was designed to control pen plotters and later adapted for large-format printers and CNC machines. HPGL commands instruct devices to move pens, draw lines, and fill areas, making it ideal for precise technical drawings and architectural blueprints.

The language uses a simple ASCII-based command structure, allowing for easy generation and interpretation by software. HPGL files typically have the .HPGL or .PLT extension and are widely supported by CAD applications and plotting software. Its vector nature ensures that graphics remain sharp and scalable regardless of output size, which is critical for engineering and design industries.

Despite the rise of modern formats like PDF and SVG, HPGL remains relevant in legacy systems and specialized manufacturing environments. Its simplicity and reliability have ensured its longevity, particularly in industries where precision and compatibility with older hardware are paramount. Many modern plotters still support HPGL through emulation modes, bridging the gap between historical and contemporary workflows.