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.

The Interplanetary File System (IPFS) is a decentralized network protocol for sharing hypermedia in a distributed file system. IPFS can be used to link blockchain transactions This effectively timestamps and secures the content, without having to put the data on the chain itself. Filecoin, an IPFS-based decentralized storage cloud, is closely related with the IPFS protocol, and provides the incentive system.