Parity Technologies is an influential blockchain development company that offers a variety of open-source software solutions for creating and using decentralized technologies. Some of their solutions include Ethereum and Bitcoin clients, cross-chain technologies, smart contracts, testnets, and cryptocurrency wallets. The company was created by Gavin Wood, the co-founder of Ethereum.

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.

RealTract is developing a smart contract platform based on a Directed Acylic Graph (DAG) protocol. They hope to create a faster and more scalable smart contract platform that can handle more use cases. The RealTract network is currently powered by the Ethereum-based RET token.