Solana is a blockchain platform designed to host decentralized, scalable applications. Founded in 2017, it is an open-source project currently run by Solana Foundation based in Geneva, while the blockchain was built by San Francisco-based Solana Labs.
Tezos is an open-source platform for assets and applications that can evolve by upgrading itself. Stakeholders govern upgrades to the core protocol, including upgrades to the amendment process itself.
Threshold is a decentralized, open-source blockchain platform that uses a proof-of-stake (PoS) consensus algorithm and sharding technology to enable fast and scalable transactions.