Old Hinduism .
The most ancient form is Vedic, attested in its earliest form in parts of the Rig Veda , dating from the late 2nd millennium BC. Late Vedic Sanskrit was described and codified in a grammar by Panini, dating from about the 5th century BC. Literary activity in so-called Classical Sanskrit, in many respects similar to the language described by Panini, flourished с 500 BC–с AD 1000. Today Sanskrit (now usually written in the Devanagari script) serves as a learned language and lingua franca for Brahman scholars. It is an archaic {{link=Indo-European languages">Indo-European language with an elaborate system of nominal and verbal inflection.