The Matic Network is a sidechain based scaling solution for public blockchains. Matic aims to allow developers to better scale their Ethereum DApps by using a version of Plasma, along with side chains that use a PoS consensus mechanism. Matic plans on supporting other blockchains as well in order to facilitate interoperability.

Ignis is a blockchain platform that is being developed by Jeluirda; the company behind Ardor and Nxt. Ignis is a child chain of the Nxt blockchain. Jelurida is developing blockchain platforms that will enable users to develop decentralized applications, and will be based on a parent and child chain architecture.
Ignis allows users to create child chains with specific features and to create tokens that meet their needs. This project is closely related to Ardor and Nxt.

BOScoin is a South Korean company that is developing a self-evolving cryptocurrency platform for trust contracts. It uses an embedded decision-making system called Congress Network and has a Proof-of-Stake (PoS) consensus mechanism. BOScoin is working to construct an algorithm for smart contracts that will ensure binary responses. BOScoin tries to solve this problem of undecidability of smart contracts by using a domain-specific language understandable by the average user. It also tries to mathematically demonstrate the decidability of its smart contracts’ implementation. To do this, they've introduced the concept of Trust Contracts; which are securely executable contracts based on a technology called Owlchain.