Nxt is a blockchain platform with multiple core-level features that has been running publicly since late 2013. It is coded from scratch in Java, unlike most of the other platforms launched at the time. It's 100% Proof of Stake, meaning that the more NXT you have the higher chances you have of processing the next block. Because it's not dependent on computational power, a full node can run on something as light as a Raspberry Pi.
Only 1 billion tokens were created and since there is no inflation, there will be no new coins created. So, when blocks are forged, (mining in Nxt) only the transaction fees are given as a block reward.