As a long time CAD user I was surprised to learn that a CAD kernel exists as a concept and that the same kernel is licensed and used in competing CAD packages.
Solidworks, Siemens NX, and OnShape all use the Parasolid kernel.
Inventor and Fusion360 use the ShapeManager kernel.
Solidworks, Siemens NX, and OnShape all use the Parasolid kernel.
Inventor and Fusion360 use the ShapeManager kernel.
https://en.wikipedia.org/wiki/Geometric_modeling_kernel