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.

Celer Network is developing a layer-2 scaling platform that aims to enable fast and secure off-chain transactions and off-chain smart contracts. The Celer Network hopes to enable developers to create scalable DApps by increasing the off-chain functionalities of blockchains.