Dhaka, Feb. 21 -- A script devised by a teenage boy in the hills of Bandarban in the early 1980s has quietly crossed into the digital age, finding a place on Google Play and computer keyboards in a rare survival story at a time when linguists warn that one language disappears every day.

The Mro language, once transmitted only through speech, is now written, printed and shared online. Books are published in its script, essays and stories appear in magazines, and villagers - from students to jhum cultivators - post in their mother tongue on Facebook.

Until a few years ago, Mro could be written only with pen and paper. Today, it exists on smartphones, laptops and social media platforms, offering new life to a language long regarded as enda...