The STEPNCWrite library writes STEP-NC toolpath data (AP238 CC1). This C++ library is completely open-source and is released under the GNU General Public License (GPL).

The library writes data in XML format (ISO 10303-28) using printf(), so it does not depend on any STEP toolkit. It has no other dependencies and should build on Windows, Linux, Mac, or any other Unix platform.

To view your toolpath files, you can use the open-source Java AP-238 Toolpath Viewer.

The AP238 conformance class one (CC1) toolpath data made by this library is the simplest type of STEP-NC file. Much more information is possible. For example, CC2 adds CAD geometry, CC3 adds features and feature-based programming, CC4 adds GD&T data. These more advanced descriptions generally require a tool like STEP-NC Machine, which can merge your tool paths with workpiece, fixture, and tool CAD geometry, add part tolerances, simulate machining, and drive existing CNC controls.