A geometric modeling kernel is a solid modeling software component used in computer-aided design (CAD) packages. Available modelling kernels include: * ACIS is developed and licensed by Spatial Corporation of Dassault Systèmes. * SMLib is developed by Solid Modeling Solutions. * Convergence Geometric Modeler is developed by Dassault Systèmes. * Parasolid is developed and licensed by Siemens. * Romulus was a predecessor to Parasolid. * ShapeManager is developed by Autodesk and was forked from ACIS in 2001. * Granite is developed by Parametric Technology Corporation. * C3D Modeler is developed by C3D Labs, part of the ASCON Group. * CGAL is an opensource Computational Geometry Algorithms Library which has support for boolean operations on Polyhedra; but no sweep, revolve or NURBS.