Cardano is another smart-contract platform, which uses proof-of-stake, that is aiming for debit card use to enable real world spending and usage.
NEO is known as "China's Ethereum" (formerly AntShares) and in addition to the features of Ethereum also adds asset, commerce and identity features.
Stellar is a pre-mined chain that has tokens (Lumens) in competition with Ripple - it is a payment remittance service.
IOTA is a "blockless blockchain" technology for the Internet of Things, has no transaction fees and is one of the fastest "blockchains"