Open CASCADE Technology (OCCT) is an open-source C++ library that provides the 3D geometry kernel for computer-aided design, manufacturing and engineering applications. Developers use it to create, edit and export solids and surfaces. OCCT is not sold as a stand-alone end-user program; it is embedded in other software. Open CASCADE also offers services and support around the technology to companies that build on it.
Open CASCADE is a French developer headquartered in Guyancourt. It has been part of Capgemini Engineering since 2014, and Capgemini is headquartered in Paris, so the owner is not foreign. The library is released under the LGPL 2.1 with an exception, which lets organisations use and modify it without placing their own software under the same licence. The kernel runs locally, so geometry does not leave the organisation's environment. For a European organisation, OCCT is therefore a sovereign building block, where the main attention goes to maintaining the application built on it and the library version it uses.