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.

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.