If you are considering Qtum, it is nothing but the open sourced public blockchain platform which controls the UTXO security while enabling the various virtual machines such as the revolutionary x86 VM and EVM. This online platform is actually based of PoS and also enhances the DGP (Decentralized Governance Protocol) which allows the particular blockchain settings to be modified by just using the smart contracts. For instance, Qtum block size can be easily increased without the necessary of the hard fork. In this blockchain platform, there are various things possible such as smart contract, UTXO model, value transferring and proof of stake. It is considered to be the business friendly and smart contract platform providing the stable, standardized and safe development environment for the smart contracts and also to enable the smart & business friendly contract coding, deployment and also execution. It is as well as the decentralized application platform which is compatible with the current blockchain infrastructure.