The animal on the cover of JavaScript: The Definitive Guide, sixth edition, is a Javan rhinoceros. All five species of rhinoceros are distinguished by their large size, thick armor-like skin, three-toed feet, and single or double snout horn. The Javan rhinoceros, along with the Sumatran rhinoceros, is one of two forest-dwelling species. The Javan rhinoceros is similar in appearance to the Indian rhinoceros, but smaller and with certain distinguishing characteristics (primarily skin texture).
Rhinoceroses are often depicted standing up to their snouts in water or mud. In fact, they can frequently be found just like that. When not resting in a river, rhinos will dig deep pits in which to wallow. Both of these resting places provide a couple of advantages. First, they give the animal relief from the tropical heat and protection from blood-sucking flies. (The mud that the wallow leaves on the skin of the rhinoceros also provides some protection from flies.) Second, mud wallows and river water help support the considerable weight of these huge animals, thereby relieving the strain on their legs and backs.
Folklore has long held that the horn of the rhinoceros possesses magical and aphrodisiac powers, and that humans who gain possession of the horns will also gain those powers. This is one of the reasons why rhinos are a prime target of poachers. All species of rhinoceros are in danger, and the Javan rhino population is the most precarious. Fewer than 100 of these animals are still living. At one time, Javan rhinos could be found throughout southeastern Asia, but they are now believed to exist only in Indonesia and Vietnam.
The cover image is a 19th-century engraving from the Dover Pictorial Archive. The cover font is Adobe ITC Garamond. The text font is Linotype Birka; the heading font is Adobe Myriad Condensed; and the code font is LucasFont’s TheSans Mono Condensed.
