Recently I needed a software which can convert English transcript in Indian languages -- more specifically in Hindi. Being the pidgin user, I tried to look for a plugin for pidgin but to my luck, there was none except one which does translation for tamil called ezuththaaNi but even that one was poorly written and causes pidgin to crash very frequently. So I decided to write one for hindi. Not to my luck again just before submitting the plugin (which suprisingly turned out very well) to pidgin community I found one free language software which translate English transcript in many indian languages and can do it for any application. Basically it reads any keyboard input and convert it to selected language unicode.
Further to its credit, you can select which application you want to use native language and also can switch between english and native language with a hotkey. This software is called Baraha. You can know more about it here.
Note: Unfortunately for pidgin users, it doesn't works well. May be if I get some time, I will update my plugin for other languages (or if you want to do it, just let me know) and upload it.