The Polkadot blockchain is a multi-chain blockchain that is designed to bundle multiple chains together so that they can be executed in parallel. The goal is for every block on the Polkadot blockchain to contain multiple blocks from other chains. This will enable the network to contain the transaction information from multiple chains and dramatically increase the overall interoperability between different blockchain networks. Polkadot was created by the Web3 Foundation, which is led by Gavin Wood, one of the founders of Ethereum. Polkadot is their flagship project, and aims to solve the issues in the blockchain ecosystem related to disjointed governance and interoperability.

RChain is building a cross-chain blockchain platform that hopes to improve transaction speeds and scalability. RChain smart contracts are written in Rholang and are run concurrently on the Rho Virtual Machine. Rholang stands for reflective higher-order language, and supports internal concurrent programming to improve smart contract processing.
Rchain supports multiple blockchains on the same node, allowing them to interact and enabling secure cross-chain exchanges of value. It uses a Proof of Stake consensus algorithm and a form of compression called LADL (Logic as a Distributive Law) that is meant to improve DApp performance.
Unlike most blockchains that use public keys to distinguish virtual address spaces, RChain divides its virtual address space into namespaces A namespace is a set of named channels that are used to communicate the location of a network resource. Namespaces allow smart contracts on one blockchain to be visible to system contracts elsewhere on the network. Namespace developers can also use tools and properties to improve system encryption and protocols.
The platform is powered by the RHOC token.

Hshare is the token that was released in an ICO for the development of the Hcash (Hyper Cash) project. Hcash will be a dual-chain cryptocurrency that will have a side chain for both blockchain-based and other decentralized networks. Hcash is a community driven platform that is designed to exchange value and data across these platforms. Hcash's dual sidechain consists of a blockchain and a Directed Acyclic Graph (DAG) network. It's designed to facilitate exchanges of value between blockchain-based and non-blockchain decentralized systems with a high degree of privacy and encryption. Hcash's dual networks will offer addresses that are inter-operable with other common cryptocurrencies, allowing users to send and receive various currencies in their Hcash wallet.
Hcash has a hybrid PoW and PoS consensus algorithm that combines verification and governance features of both mechanisms.