Indic transliteration for the visual editor.
Current only Devanagari, Bengoli, Gujarati, Kannada, Malayalam, Gurumukhi, Telugu and Urdu are supported. If you would like to help with the support of another script, please see the web site of the Gamabhana library for more details and instructions.
You can find some helpful hints in this Wikipedia page.
Have a look at the nice table at the Gamabhana library site. Devanagari is used there, but the same logic applies to all other scripts.