IGS (Initial Graphics Exchange Specification)

IGS is an open file format used within CAD applications as a means of saving data in a format that can be opened and edited in other CAD applications. Its roots can be traced back to the mid-1970s, when it was used by the United States Air Force.

The format itself is a human-readable text-based format and contains data that can represent many different CAD elements, such as points, lines, arcs, and much more. IGS files can be opened with many modern CAD applications, such as FreeCAD.