Nxt is a blockchain platform developed by Jelurida, which is also developing the Ardor blockchain. Nxt's goal is to improve upon existing blockchain platforms with a modular toolset that enables users to create their own digital assets that can be listed on decentralized marketplaces. Nxt also features community driven voting mechanisms and has an architecture that separates the blockchain into parent and child blockchains.
The network is powered by the NXT token and has a Proof-of-Stake (PoS) consensus mechanism.

Lisk is a blockchain-based platform that allows developers to build and publish their own applications. Lisk uses sidechain development kits, that are written in Javascript, to enable users to create their own blockchain applications according to their needs. Each decentralized App runs on its own sidechain that can be customized, and is connected to the Lisk blockchain, which has a Delegated Proof-of-Stake (dPoS) consensus mechanism. The Lisk network is powered by the LSK coin.

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.