Their range is much of Southeast Asia (northeast India, Vietnam, southern China, Borneo, Thailand, Java, and Bali).

The name "lutung" comes from the Sundanese language meaning "blackness", ultimately from Proto-Austronesian *luCuŋ (which originally referred to the Formosan rock macaque);[2] it is preferred in one paper because the authors wanted the name langurs to only refer to monkeys in the genus Semnopithecus,[3] although some "lutungs" are now "langurs" again.

[4][5][6] Genetic analysis indicates that the ancestors of the modern species of lutung first differentiated from one another a little over 3 million years ago, during the late Pliocene.

The various species alive today then diverged during the Pleistocene, presumably driven by habitat changes during the Ice Ages.

The closest living relatives of the lutungs are probably either the gray langurs or the surilis, although the exact relationships remain unclear, possibly due to hybridisation between these genera during the course of their recent evolutionary history.

The fur color varies, depending on the species, from black and grey to orange yellow.

Many species have skin designs and a brighter lower surface, the hair on the head is often compared to a hood.

The inner surfaces of the hands and feet are hairless so that their fur does not get caught when reaching into branches.

These animals reach a length of 40 to 80 cm and a weight of 5 to 15 kg, with males generally larger than females.

Rarely twins, a typical single birth comes after a seven-month gestation period.

The mother shares responsibilities of rearing the young with the other females ("aunties") of the harem.

They hand the young around, play with it, carry it, and cuddle it, while the mother searches for food.