Kusama coin is the native coin of the Kusama blockchain, which is intended to serve as an unaudited and unrefined release of Polkadot. Kusama will serve as a trail version for Polkdadot, and will allow developers to build and deploy a parachain or try out Polkadot’s governance, staking, nomination and validation functionality in a real environment.

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.

NIX is developing a cross-chain protocol with an emphasis on privacy. Their platform will be powered by the NIX coin, and will allow users to exchange supported coins with atomic swaps. Nix hopes to eliminate the need for centralized exchanges with their DEX manager. The platform is based on the Ghost Protocol, which uses elements of Zercoin, and integrates the Tor network to provide enhanced security and privacy for users. NIX allows developers create and attach their own networks to the NIX network as sidechains. The cross-chain platform has a Proof-of-Work consensus mechanism.