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.

Namecoin is a blockchain-based DNS that allows users to register domain names with a ".bit" domain. Namecoin was the first fork of the Bitcoin protocol and it aims to remove centralized control over domain registration. It was the first cryptocurrency to use Auxiliary Proof of Work (AuxPoW) as a consensus mechanism,
where a child blockchain is dependent on the Proof-of-Work consensus of the parent blockchain. This allows for Namecoin and Bitcoin to be mined simultaneously, and when a new block is created on Bitcoin, it will also be added to the Namecoin blockchain.
Namecoin is a very important project that represents one of the best use cases of blockchain technology in protecting free speech and resisting censorship on the internet. It is powered by the NMC coin. The decentralized DNS provides more security from hackers and government intervention.

ARK, which is a fork of Lisk, is developing an interconnected blockchain ecosystem that will make it easier for users to develop their own blockchains. Ark emphasizes interoperability and usability. Their moto is “Point.Click.Blockchain” and their goal is to allow for easy deployment of DApps. Ark's "push button blockchains" can be easily created with minimal programming knowledge. Ark also hopes to encourage adoption by developers by accommodating 18 different programming languages.
Ark has a delegated Proof-of-Stake (dPoS) consensus mechanism. Their governance model allows users to vote for delegates that secure the network. The top 51 delegates voluntarily share there tokens with their voters.
Ark contract execution service (ACES) connects ARK with other blockchains and will enable exchanges of value between them.