What kind of fruit is this?

[Tropicalnut]

I went on vacation to El Salvador in Central America for two weeks, and I found this fruit that I had never seen before at the beach house we staying. I asked about the name and the lady there said that they call it " Aguacoco" Do any of you know what the scientific name is? I managed to get some seeds home with me, the taste was interesting but I only ate one (since I didn't know much about it)  and the birds seemed to love them.
We also ate:
Leeches, Arrayan, Jocote de corona, Mamey, Nispero, Green mangoes, Nances, Icaco, Anonas, Guanabas, apple bananas and sapotes ( That is the name I know for them) It wasn't "fruit season" so we were happy with what we got.

[ben mango]

java plum- Syzygium cumini ..the anona fruit look nice, is it A. diversifolia ?

[Tropicalnut]

Thanks, I really don't know what kind the anona is, all I know is that we ate some white he white and pink inside, I brought seeds from both colors. I actually brought seeds from all the plants except the guanaba because I wasn't around when they cleaned it to make a drink with it.

[Raulglezruiz]

Yes ,probably Ben is right , it is also known as Jambolan; however I never seen a round ones
The ones I have seen here in Mexico and Hawaii are oval; the ones I have tried have very astringent flavor and are not good to eat out of hand; usually people only use them to do wine; on the other hand also reminds a fruit I came across from the next state where I am;
The round shape and color is the same I don't remember the leaves do people over there really like however they have a very different strong flavor; I couldn't handle it the flavor stays in my mouth for long time; maybe is an acquired taste, they are call ahualamo or agualamo....

[From the sea]

could also be a Antidesma bunius, also known as Bignay.

[Tropicalnut]

Looking at the description in the computer of both it seems more like java plum- Syzygium cumini. Too bad its too messy for home because the tree is very nice and tall. The one fruit I ate was very pleasant, not too strong but they did warned me that it made the teeth and mouth purple. :)I got about 30 seeds in case someone else is interested in gronwing it. I may try to keep one in a pot just for kicks!