Sling is a programming language for specifying plots of mathematical functions, notably slings. A real sling is a weapon that consists of a strap about a yard long and a stone that attaches to the end of the strap. With some practice and acquired skill, you can whirl a sling over your head, release the stone at the right moment, and strike a target. A famous example of the use of a sling appears in Chapter 17 of the first book of Samuel in the Old Testament. The youthful David steps forward in a battle of champions , and with a skillful shot from his sling he slays the mighty Goliath.
The Sling programming language plots the path of a sling stone as seen from above, as it rotates around the hurler's head. Slings in the Sling programming language are mathematical objects that you can manipulate in interesting ways, such as adding them together.