piecewise(6x) on Linux
The text 64c8e58740c5, as Debian 10 (Buster) shipped it.
lots of moving circles intersecting in interesting ways.
Flags it lists
-
-colorspeed -
-count -
-db -
-delay -
-fps -
-maxradius -
-minradius -
-ncolors -
-no-db -
-root -
-visual -
-window