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.

Stakenet is a blockchain with a unique Trustless Proof of Stake (TPoS) consensus mechanism that allows users to participate in the staking process without having to freeze their coins in the wallet. It's powered by the native coin XSN and is managed by its own masternodes. Stakenet (XSN) was created to build an ecosystem that allows easy and secure offline staking and cross chain communication. It has characteristics of Bitcoin, Dash and Peercoin, that were modified for their own purposes. XSN uses the Bitcoin Core, an improved Dash masternode architecture, and Peercoin's validation mechanism for creating new blocks.