Beam is a privacy-centric cryptocurrency powered by the Mimblewimble protocol. Unlike Monero or Zcash, MimbleWimble coins enforce privacy on a protocol level, rather than adding layers on top of the original blockchain to achieve privacy. This reduces the load and data stored on the blockchain, which leads to greater scalability.
Nervos Network aims to expand on Bitcoin’s core technological primitives with Common Knowledge Base (CKB), a scalable Layer-1 blockchain that enables Layer-2 support for Bitcoin. CKB employs a Proof-of-Work consensus mechanism like Bitcoin but generalizes Bitcoin’s limited UTXO model and scripting capabilities by allowing more flexible data storage and verification. To improve Bitcoin’s arbitrary programming limitations, Nervos Network leverages a custom Cell Model for state storage and a virtual machine (CKB-VM) for transaction execution.