xnlock -- Dan Heller, 1990
"nlock" is a "new lockscreen" type program... something that prevents
screen burnout by making most of it "black" while providing something
of interest to be displayed in case anyone is watching.  The program
also provides added security.

"xnlock" is the X11 version of the program.

Original sunview version written by Dan Heller 1985 (not included).

For a real description of how this program works, read the
man page or just try running it.

The one major outstanding bug with this program is that every
once in a while, two horizontal lines appear below the little
figure that runs around the screen.  If someone can find and
fix this bug, *please* let me know -- I don't have time to
look and if I waited till I had time, you'd never see this
program...  It has something to do with the "looking down"
position and then directly moving up and right or left...