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.

ChainLink is developing the LINK Network, which will enable connected smart contracts. LINK will provide smart contracts with a variety of external data and access to APIs. ChainLink's goal is to solve the connectivity problem that plagues smart contract based systems, and discourages mass adoption. Many decentralized applications are unable to connect with important external data sources due to limitations involving their consensus protocols. The LINK network wants to connect their smart contracts with external systems and APIs by using secure middleware.

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.