Indonesian is the official language of Indonesia. It is a standardized register of Malay, an Austronesian language which has been used as a lingua franca in the Indonesian archipelago for centuries. Indonesia is the fourth most populous nation in the world. Of its large population, the number of people who speak Indonesian fluently is fast approaching 100%, making Indonesian, and thus Malay, one of the most widely spoken languages in the world. Most Indonesians, aside from speaking the national language, are often fluent in another regional language which are commonly used at home and within the local community.