Holo is a decentralized hosting provider that is built on top of Holochain. DApps can be set up and deployed with Holo hosting, as a decentralized alternative to Amazon Web Services, or other centralized hosting solutions.
Holochain is a protocol for creating decentralized Apps and is different from blockchain protocols in several ways. The main difference being that Holochain takes an agent-centric approach to their consensus mechanism, and has a different approach to validating value transfers.
The HOT token is used for paying for hosting services on Holo, and users can be paid for offering their computing resources.

T‍he Flow Blockchain aims to be a developer-friendly blockchain for a new generation of DApps and digital assets that power them. Flow Blockchain is based on a unique, multi-role architecture, and is designed to scale without sharding, so that it can accommodate consumer applications with more users. The project was created by Dapper Labs, which previously created Crypto Kitties, one of the most popular blockchain collectible projects. Flow is now being used by NBA Top Shot, an officially licensed NBA platform for player related, blockchan-based collectibles. The founders: Roham Gharegozlou, Dieter Shirley, and Mikhael Naayem launched Flow with the goal of simplifying the DApp development experience.
Flow uses a Proof of Stake consensus mechanism. Flow coins are intended to be used as payment for validation services, data and computation, governance, as well as for collateral for secondary tokens that may be created on the platform in the future.

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.