Reference

XFillRectangles(3x) on Linux

The text a5990947578f, as Debian 2.2 (Potato), Debian 2.1 (Slink), Debian 2.0 (Hamm), Debian 1.3 (Bo) shipped it.

fill rectangles, polygons, or arcs

XFillRectangles(3x) on Linux now