Ethereum is an innovation network providing its own blockchain with its cryptocurrency (Ether or ETH). This blockchain hosts decentralized applications (DApps) that were first introduced by Ethereum. Another innovation of this platform is the implementation of smart contracts which has changed the perception of the possible use of the blockchain, revealing the potential of the technology to its fullest.
BitBay (BAY) digital currency has been developed since 2014 with the eponymous market place being in operation from 2015. The coin is now listed on a few exchanges. You can purchase BitBay with fiat (hard) currency, such as USD or EUR, using a bank card.
IOTA is a distributed ledger and cryptocurrency created to process operations between devices of the Internet of Things. IOTA was launched in 2015. The project is based on an unique directed acyclic graph (DAG) instead of a blockchain. DAG uses a Tangle technology which provides unlimited scaling opportunities and free and fast transactions. The project is backed by non-profit IOTA Foundation. Besides, IOTA ecosystem has its own data marketplace available both for companies and individuals. IOTA quickly gained strong partnerships in the tech industry (including Volkswagen and Bosch) and high market capitalization (by the end of 2017 IOTA reached top 5 list by its, market cap although now its position is lower).