The Elrond blockchain platform is designed to be a public development infrastructure that will be more secure, efficient, and scalable than other blockchain platforms. The Elrond blockchain is aimed at DApp developers and enterprises. Elrond will have a Prof of Stake consensus mechanism, and will include an Adaptive State Sharding feature that will allow multiple validators to process transactions in parallel.

Hedera Hashgraph is a blockchain network that was designed to allow developers to create DApps that require higher throughput and faster settlement. Hedera uses its own consensus protocol that assigns every transaction a consensus time that is calculated as the median of the times at which each node in the network first received it. The network is powered by the HBAR coin.

Kadena is a software development company that builds blockchain-based platforms for a range of businesses. They develop purpose-built blockchain solutions for their clients by using proprietary solutions that are aimed at being both secure and scalable. Kadena offers both private and public blockchain platforms, with smart contracts written in the Pact programming language. They've also developed an innovative proof-of-work architecture called ChainWeb that could have a variety of applications.
Kadena's founders have experience working for the U.S. Securities and Exchange Commission (SEC) and JPMorgan Chase Bank. The company has raised significant funding and is well positioned to be play a big role in developing future blockchain solutions for large financial institutions.