Today Kraken launched with ether trading. Ethers are the currency of the Ethereum network, which is a decentralized platform for executing programmable smart contracts. 

Out of the gate it was Kraken’s highest volume launch to date, with over 3 million ethers traded in the first week (worth over 15,000 bitcoins at the time). Kraken has quickly become the world’s second largest exchange for trading between ethers and bitcoins (ETH/XBT). Kraken also supports trading between ether and any of the fiat currencies it supports, with the highest volume in the ETH/EUR and ETH/USD pairs.