The Dusk Network is a privacy-oriented blockchain protocol that is designed for creating programmable and confidential securities. Dusk places a strong focus on privacy and aims to make it easier for developers to create digital securities and zero-knowledge DApps. The network is currently powered by the Ethereum based DUSK token.

Mainframe is creating a blockchain development platform for decentralized applications. Their marketing materials place a strong emphasis on encryption, privacy, and interoperability. Onyx, a decentralized workplace messaging tool, is the first application to be built on the Mainframe network.
Mainframe is powered by the MFT token.

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.