Chromia is a relational blockchain platform that is designed to be both a blockchain and a relational database. Chromia was created by a Swedish development company called ChromaWay, with the intention of combining the advantages of a blockchain's transparency with the benefits of a relational database system, such as data independence and reduced redundancy.

Bytom is a Chinese company that is developing a blockchain platform that is specifically designed to register securities and physical assets to the Bytom blockchain. Bytom aims to create a secondary markets for these blockchain registered assets and will allow them to be tokenized.
Bytom is compatible with other platforms and enables high transaction speeds and anonymity.
One of Bytom's key features is its improved PoW consensus algorithm that is compatible with AI-enhanced ASIC chips. This allows for more efficient mining that uses less energy.

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.