Aeternity is a smart contract driven blockchain platform that aims to integrate real world data and improve the overall performance of smart contracts. Aeternity has a hybrid consensus algorithm that combines PoW for verifying transactions, and PoS for governance purposes. The platform is based on a system of state channels that allow users to interact privately with each other and record this information off-chain.

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.

Nethereum is an open source .NET integration library for Ethereum. It is designed to help developers easily integrate the Ethereum blockchain into their .NET applications. It consists of modular libraries for features that are covered are writing smart contracts, cryptographic wallets, DApps, and managing blockchain data.