NEO, formerly known as AntShares, is one of the leading smart contract enabled blockchain platforms that allows for the development of digital assets. Similar to Ethereum, NEO uses two different tokens: NEO and GAS, each of which have a specific purpose on the network. NEO tokens give holders a share in the ownership of the NEO blockchain, and when they are held in a compatible wallet, they are rewarded with GAS tokens. NEO has a Delegated Byzantine Fault Tolerance (dBFT) consensus algorithm that has uses some features of PoS, and is designed to be more scalable than other consensus mechanisms.

IOST (Internet of Services Token) is a blockchain platform that is focused on improving transaction speed and scalability. IOST has a unique Proof of Believability consensus mechanism that is based on past contributions and behavior.
The company claims that their platform will increase security and efficiency compared to other platforms. IOST uses a sharding technique that splits the network into smaller ones and randomly assigns tasks for the nodes on the network.

Ubiq is an Ethereum fork that aims to create a more stable smart contract platform for building DApps. Ubiq's protocol currently uses a Proof-of-Work (PoW) consensus mechanism, but will switch to Proof-of-Stake in 2019. The network is powered by the UBQ coin.
Ubiq's goal is to create a reliable and stable platform for developing DApps by modifying Ethereum's code base with important changes that will make it more secure and reduce instability. Consensus is based on their Flux Difficulty Algorithm, which is designed to constantly adjust the hash rate to protect against network attacks.