What is NURBS?
NURBS, Non-Uniform Rational B-Splines, are mathematical representations of 3-D geometry that can accurately describe any shape from a simple 2-D line, circle, arc, or spline curve to the most complex 3-D organic free-form surface or solid.

Because of their flexibility and accuracy, NURBS models can be used everywhere from illustration and animation to manufacturing.

Why NURBS technology?
NURBS is the best 3-D modeling technology for designers. They can capture and refine ideas and accurately communicate them through every step to manufacturing. With NURBS, designers can model any shape from a simple 2-D arc to the most complex 3-D organic free-form surface, or solid.

Because of their accuracy, NURBS can be used in any process from drafting, illustration, and animation to analysis and manufacturing.

Since NURBS is proven technology, it is used by most design, drafting, CAM, engineering, prototyping, analysis, rendering, animation, and illustration software.

For more details, see these books and papers.

Who designed the file format and developed the toolkit?
McNeel. The toolkit is currently being used by Rhino and over 4,500 other developers.

What is in the file format?
It is the complete Rhino file format, which includes NURBS curves, surfaces, and solids, annotation, images, and meshes. These data types can accurately hold all of the 3-D geometry found in most other CAD/CAM file formats including IGES, STEP, VDA/FS, ACIS, Parasolid, etc.

Who is funding the openNURBS Initiative and why?
Robert McNeel & Associates. They feel that the 3-D market is stifled because of the inability to reliably transfer 3-D geometry between applications. The problem is too big for us to solve alone. By funding the operating cost of openNURBS, others will get involved in the toolkit design and development. It will be a much cheaper and effective way to solve the problem.