Rayshade is public domain code developed by many people, but most notably Craig Kolb (cek@cs.princeton.edu). There are three versions:

Rayshade 4.0

is installed on the Suns (with minor enhancements by mwm (me); depth map, rle2gil, gil2rle). Original source is in /alex/edu/princeton/pub/Graphics/rayshade.4.0/ rayshade.4.0.tar.Z

Rayshade 4.0.6

is installed in a CS misc collection

Rayshade 4.0.6enh

is an ``enhanced'' version; many users' extensions were combined into this (unsupported) package by Dave DeBry (ddebry@dsd.es.com). This is not installed at CMU, but you can find it in /alex/edu/yale/math/weedeater/incoming/ray406enh.tar.Z