Qtum is a public proof-of-stake (PoS) blockchain protocol that is based on the code of Bitcoin but has been modified to allow smart contracts to run on top of its UTXO (unspent transaction output) model. The blockchain can connect to multiple virtual machines (VMs) at the same time thanks to Qtum Neutron. This enables Qtum to use the Ethereum Virtual Machine (EVM) as well as its own cutting-edge x86 VM while leveraging the capabilities of its 1,000-node blockchain network.