These are executable programs; download them in binary mode, and you may have to change permissions on them to get them to execute:

chmod a+x program-name

For Susan and Ed: the shadow program is on uwast.astro.wisc.edu in ~jwp/bin/Linux or ~jwp/bin/ppc (Mac OS X pre-Intel). Intel versions are coming soon.

For the WOCS crowd: the sun_position program is on uwast.astro.wisc.edu in ~jwp/bin/Linux or ~jwp/bin/ppc (Mac OS X pre-Intel). Intel versions are coming soon.