The oldest datable writing systems for Sanskrit are the Brāhmī script, the related Kharoṣṭhī script and the Brahmi derivatives. The Kharosthi was used in the northwestern part of South Asia and it became extinct, while the Brahmi was used in all over the subcontinent along with regional scripts such as Old Tamil. Of these, the earliest records in the Sanskrit language are in Brahmi, a script that later evolved into numerous related Indic scripts for Sanskrit, along with Southeast Asian scripts (Burmese, Thai, Lao, Khmer, others) and many extinct Central Asian scripts such as those discovered along with the Kharosthi in the Tarim Basin of western China and in Uzbekistan. The most extensive inscriptions that have survived into the modern era are the rock edicts and pillar inscriptions of the 3rd-century BCE Mauryan emperor Ashoka, but these are not in Sanskrit.