Cypherium

Basics

"Cypherium is a highly scalable and robust smart contract platform. Our hybrid design features a joint Proof-of-Work (PoW) and HotStuff (Also adopted by Facebook's Libra) consensus mechanism that can achieve thousands of transactions per second without sacrificing decentralization. Cypherium also implements a Turing-complete virtual machine for smart contracts that runs on Java"
Claims to have an ASIC-resistant PoW system.
Claims no minimum fees for smart contracts
Claims no fixed block size.
Has implemented Schnorr Signatures as ED-25519, "Cypherium’s digital signature mechanism is faster, smaller, and more reliable than Bitcoin's ECC algorithm."

Whitepaper can be read here.
"Building off Bitcoin-NG and ByzCoin protocols, an election chain chooses Proof-of-Work leaders to write new blocks, while a transaction chain uses HotStuff consensus to verify the transaction data within those blocks."

"The leader node (crown) proposes a block and waits to be verified by validating nodes.
If 2/3 of the quorum is reached, the block is accepted into the blockchain.
Following its acceptance, the new block is then broadcasted to all nodes.
Honest, verified nodes will then reject all messages from nodes without PoW.
Cypherium achieves scalability by electing the voting committee to separate PoW from the transaction verification process, with bandwidth limited only by the capacity of the individual nodes and latency limited only by the propagation time of the network."

"The Cypherium Virtual Machine revolutionizes smart contract technology with four notable innovations that improve the industry standard for Ethereum Virtual Machine (EVM):

Dalvik Architecture.Instead of using the existing stack-based architecture, we use the register-based Java Dalvik architecture that was created for the Android OS, which is more lightweight and able to run on mobile devices.
Faster data types. All EVM data types are based on 256-bit words. The Cypherium Virtual Machine supports native 64-bit integers, which is exponentially faster than EVM.
Built-in safety checks. Cypherium performs Safemath safety checks at the virtual machine level, so vulnerabilities commonly found in EVM can be detected by CVM.
Fixed-point representation is part of what enables low-cost, embedded chip-technology in payment cards, which is a crucial part of modern business transactions. Where traditional EVMs lack this technology, CVM does not."