The Reserve protocol comprises two tokens: the Reserve token (RSV - a decentralized stablecoin) and the Reserve Rights token (RSR - a cryptocurrency used to facilitate the stability of the Reserve token and confers the cryptographic right to purchase excess Reserve tokens as the network grows).
NXT is one of the early cryptocurrencies and was started in 2013. As the Jelurida project’s website states, it was the “first to rely entirely on the PoS protocol”. It is currently listed by the number of exchanges.