QCAD is a free, open source application for computer aided drafting (CAD) in two dimensions (2D). With QCAD you can create technical drawings such as plans for buildings, interiors, mechanical parts or schematics and diagrams. QCAD works on Windows, Mac OS X and Linux.
QCAD was designed with modularity, extensibility and portability in mind. But what people notice most often about QCAD is its intuitive user interface. QCAD is an easy to use but powerful 2D CAD system for everyone. You don't need any CAD experience to get started with QCAD immediately.
The source code of QCAD is released under the GPL version 3 (GPLv3), a popular Open Source license.