libnurbs is described as 'C++ NURBS library' and is an app in the Development category. There are three alternatives to libnurbs for Linux and Windows. The best alternative is openNURBS, which is both free and Open Source. Other great apps like libnurbs are NURBS++ (Free, Open Source) and SISL (Free, Open Source).
Non-Uniform Rational B-Splines (NURBS) curves and surface are parametric functions which can represent any type of curves or surfaces. This C++ library hides the basic mathematics of NURBS. This allows the user to focus on the more challenging parts of their projects.