Lansium Domesticum is the scientific name for Duku Langsat (Malay). They grow in clusters, about the size of very large Red Globe grapes, pale yellow skin with about 5-6 segments of soft, translucent white and juicy flesh. Taste on the tangy sweet side and usually one swallow the slippery seeds together with the flesh as it's just too troublesome to remove the seeds from the flesh. It's perfectly all right to swallow the seeds whole and nope, your head won't grow tree after swallowing them hahaha... it's a childhood joke that my grandma loved to pull on us.
Based from the short description found in Wikipedia, Duku Langsat is also known as Duku or Langsat. For other names in the various languages, check here. Well, I always get confused and I can't really tell the differences of the various species in the family of duku, langsat, dokong, duku langsat etc... It's not something that I would buy and eat hehehe cos I don't really like them cos the skin have some milky latex that make my fingers really sticky. Read here on the comparison of these fruits. These are seasonal fruits and currently they're in season in Malaysia.
If you would love to read more details, click here.