Richard Wright wrote:
Can somebody please identify the species of fruit tree included in
images at:

http://www.box.net/shared/static/seh2oklc0g.jpg

The place is East Timor. Photos taken last week.

The locals said that the fruit was 'starvation food' among those
people who took to the hills at the time of the Indonesian invasion.

Note the spines on the branchlets.

The skin of the fruit is hard, like that of a pomegranite.

The texture of the pulp is sticky, the flavour somewhat like that of
Passiflora edulis or passion fruit.
I believe it's Aegle marmelos, the baelfruit, which, as Monique
suggested, is Rutaceae.