Read "Idli Saga:A study into the origin of the South Indian dish" in the April 28th edition of "The Economic Times". The article basically says iDli or iDDalige originally a Karnataka dish, mentioned in the10th century works, was taken to Indonesia by South Indian traders and there it gave rise to many fermented dishes like kedli. Of course, the author of that column quotes a bit different story from the research work of K T Acharya.
