There are quite a few trees that fruit for me in the shade but most of them developed with decent sun which for us is minimum 3-5 hours per day.  after growing some of the areas got shadier as my growing areas are seperated by forest corridors.  Many of these trees still produce including champedak, achacharu, mangosteen, and several others.  the only very good quality fruit tree that comes to mind that will develop nicely under the canopy is salak.  Vanilla will take about 3 years to start producing.  You can learn to pollinate it very easily, what is more complicated is doing a good job curing it.
Peter

Hi Durian lover-  I live in an area that is easy to visit.  I sometimes have accomodation available and there are also lots of small hotels and restaurants in the area.  I am in Puerto Viejo, Limon and it is easy to reach by direct bus or rental car from San Jose, the capitol.  There are lots of tourists around here at the moment but not much fruit.  In September/October it is the opposite.
Peter

Hi, I am Peter from the Caribbean coast of Costa Rica.  I know some of you from visits to my farm and others from other groups.  I have been growing tropical fruits, spices and ornamental plants since 1987 in my present location.  My farm is 18 hectares but most of that is rainforest.  We are situated at about 9 degrees North in an area with 4m of rainfall which is well distributed in two primarily dry seasons and two wet seasons.  I feel that the weather is very similar to peninsular Malaysia and parts of Borneo.  I practice agro-forestry and have a collection of more than 150 fruit and spice trees.  My farm is commercial and I sell fresh fruits, spices, and fine chocolate as well as run a nursery of fruit trees and ornamental plants.  Saludos from Costa Rica, Peter