The illustrations that appear in the book were created in Macromedia Freehand 5.0 by Chris Reilley. The animal featured on the cover of UNIX Systems Programming for SVR4 is a lion, a large, carnivorous cat inhabiting western India and Africa south of the Sahara. The most sociable of cats, lions live in prides consisting of one to four males and a collection of up to thirty females and cubs. However, the members of a pride are seldom all together at one time, instead moving about their territory as individuals or small groups. A pride's territory may be anywhere from 15 to 150 square miles, depending on the abundance of food, and is marked by scent and roaring.
Lions eat both fresh kill and carrion-dead animals or the kill of other animals.
When they do kill, they show a preference for large prey such as zebra or wilde beest which will feed the entire pride. Females do the majority of the hunting, frequently working cooperatively to encircle or bring down large game. During the hunt, lions are careful to move under cover of darkness or foliage, but tend to disregard the wind direction and thus frequently give themselves away.