Ubiq is an Ethereum fork that aims to create a more stable smart contract platform for building DApps. Ubiq's protocol currently uses a Proof-of-Work (PoW) consensus mechanism, but will switch to Proof-of-Stake in 2019. The network is powered by the UBQ coin.
Ubiq's goal is to create a reliable and stable platform for developing DApps by modifying Ethereum's code base with important changes that will make it more secure and reduce instability. Consensus is based on their Flux Difficulty Algorithm, which is designed to constantly adjust the hash rate to protect against network attacks.

Emercoin is a blockchain-based development platform. It has developed a range of easy-to-use dSDKs (Decentralized Software Development Kits) that can be used to more easily build DApps. This set of software development tools allow the creation of blockchain-based software and services.
Emercoin's dSDKs have been implemented in several innovative DApps and provide developers with solutions for a variety of functionalities. Some of the dSDK's that Emercoin offers are specifically geared for decentralized DNS, SSH, SSL, and DPO solutions.
Emercoin has a hybrid consensus mechanism that combines elements of Proof-of-Stake (PoS) with a Proof-of-Work (PoW) algorithm that is merge-mined with Bitcoin. The network is powered by the EMC coin.

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.