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.

The Elrond blockchain platform is designed to be a public development infrastructure that will be more secure, efficient, and scalable than other blockchain platforms. The Elrond blockchain is aimed at DApp developers and enterprises. Elrond will have a Prof of Stake consensus mechanism, and will include an Adaptive State Sharding feature that will allow multiple validators to process transactions in parallel.

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.