PLY_IO is a C library which reads and writes files in the PLY format, for objects described as collections of polygons, by Greg Turk.
PLY_IO is available in a C version and a MATLAB version,
OBJ_TO_PLY, a C program which converts an OBJ file to a PLY file.
PLATO_PLY, a C program which writes out any of the five Platonic solids as a PLY file.
PLY, a data directory which contains some information about the PLY format.
PLY_DISPLAY, a MATLAB program which displays an image of a 3D graphics file in PLY format;
PLY_TO_IV, a C program which converts a PLY file to an Inventor file.
PLY_TO_OBJ, a C program which reads a PLY 3D graphics file and writes an equivalent OBJ graphics file.
PLY_TO_TRI_SURFACE, a MATLAB program which can read a PLY file, extract the polygonal surface information, and return it as a TRI_SURFACE dataset.
TRI_SURFACE_TO_PLY, a MATLAB program which converts a TRI_SURFACE data structure into a PLY data structure.
You can go up one level to the C source codes.