SoVRMLNormalInterpolator(3) on Linux
The text bdacab95ddcd, as Debian 6.0 (Squeeze) shipped it.
The SoVRMLNormalInterpolator class is used to interpolate normals. The detailed class documentation is taken verbatim from the VRML97 standard (ISO/IEC 14772-1:1997). It is copyright The Web3D Consortium, and is used by permission of the Consortium:.