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.

ConsenSys is one of the most influential blockchain technology companies. They are working on a variety of projects to create the infrastructure and applications that will enable scalable adoption of blockchain-based systems. The company's efforts are focused on the Ethereum ecosystem, and include divisions working to advance technology development, establish industry standards, and provide consulting, marketing, and education services.

Hydrogen is a fintech company that develops API' for creating financial applications. They are developing the open-source Hydro blockchain platform that emphasizes identity management and security. The network is powered by the Ethereum-based HYDRO token.