SFView
SFView (Surface Viewer) is a utility that I needed very much - it loads NxM grids of 3d points or NURBS surfaces and displays them in a common OpenGL window. There are several display modes, including slicing map, isophote map and mean curvature map, and it can also take PNG screenshots with transparent background.
It handles RBN (see CL-NURBS for its specification) and PTS files. The latter one is of the format:
I tried to follow the GNU standards while making this, so it has all the standard command line arguments and also a manual page.
Download the source code for version 0.35 or get the latest with Mercurial: