QCAD

QCAD is a free, open‑source application for computer‑aided drafting in two dimensions. It runs on Windows, macOS and Linux and is released under GPL v3. The program lets users create technical drawings such as architectural plans, interior layouts, mechanical parts, schematics and diagrams, supporting both metric and imperial units.

The interface is designed to be intuitive, allowing people without prior CAD experience to start drawing quickly. It provides a full set of construction and modification tools for points, lines, arcs, circles, ellipses, splines, polylines, text, dimensions, hatches, fills and raster images, along with layers, blocks, snapping, measuring and a library of over 4 800 CAD parts. QCAD can import and export DXF and DWG files, print to scale, and generate multi‑page outputs.

Extensibility is offered through an ECMAScript (JavaScript) scripting interface and command‑line utilities for format conversion and G‑Code export via QCAD/CAM. The modular design emphasizes portability and the ability to add custom functionality.