Cardstack is a blockchain technology company that is developing an open-source framework and consensus protocol to make blockchains more usable and scalable. Their goal is to create a decentralized modular smart contract ecosystem. The Cardstack network is powered by the Ethereum-based CARD token.

Harmony is developing an open consensus blockchain platform. Harmony's sharding-based consensus mechanism is designed to scale as the number of nodes increases in the network. Harmony aims to tackle issues related to scalability by optimizing across multiple layers in a way that will enable parallel transaction processing with reduced latency. Harmony is currently powered by the ONE token, which is built on the Binance blockchain.

Nxt is a blockchain platform developed by Jelurida, which is also developing the Ardor blockchain. Nxt's goal is to improve upon existing blockchain platforms with a modular toolset that enables users to create their own digital assets that can be listed on decentralized marketplaces. Nxt also features community driven voting mechanisms and has an architecture that separates the blockchain into parent and child blockchains.
The network is powered by the NXT token and has a Proof-of-Stake (PoS) consensus mechanism.