Can somebody who has the knowledge help me?? Recently I read a wiki article on the cross platform messaging app whatsapp. Now what caught my eye was that this app was written in erlang. Since android apps are written in java, iOS and windows mobile os apps are written in c# then how on earth did whatsapp arrive on smartphones since it wasn't written in the native language that these smartphones os recognise. Like, can erlang be converted into java??? Or did the debs for whatsapp implement the erlang code on the appropriate hardware and then decided to code the app for smartphones sort of client like, in that all apps regardless of the language would work the same way they would across various platforms?????