The durian is a type of tropical fruit.
The durian tree grows up to 40 metres in height and durians can hang from any branches, and a typical durian can weigh 1-2 kg, so a durian plantation during durian season is hardhat territory. A durian breaking a 20 metre fall directly on your head can be very bad for your health!
The durian is native to Malaysia and Indonesia although it can grow in any similar climate (there have been some successful durian plantations in Queensland, Australia). The fruit is green to brown, oblong to round, prickly with strong sharp thorn and emits a strong distinctive durian smell that puts most foreigners off. It is often called the "king of fruits" by locals.
The scientific name for the durian is Durio zibethinus Murr.
There are many clones of the durian, all having a name starting with D and a number. For example, some popular clones are D24, D99, D158 and D159 (this is the 'Mon Thong' variety).
more info: http://www.ecst.csuchico.edu/~durian/
See also how to choose a good durian