Peercoin (PPC)

Peercoin (PPC) launched in August 2012 and was the first cryptocurrency to introduce proof-of-stake, a consensus design now used across much of the industry. It runs a hybrid model: proof-of-work distributes new coins, while proof-of-stake secures the chain and pays a minting reward to holders who keep a wallet online. Transaction fees are fixed per kilobyte and are burned rather than paid to a miner, which ties the coin supply to how much the network is actually used.