Quorum is a fork of Ethereum that supports private and permissioned transactions. While public Ethereum blockchains are open and transparent, Quorum blockchains can be configured to be private and permissioned, meaning that only approved participants can access the blockchain and view its contents.
Transactions on Quorum are also faster and more scalable than on public Ethereum blockchains.
Quorum was created by JPMorgan Chase as a way to streamline their internal blockchain applications, but it is now an open-source project with contributions from a variety of organizations. JPMorgan Chase is still the largest contributor to the Quorum project.
While Quorum does run on Ethereum, it is not compatible with all Ethereum applications. For example, Quorum does not support smart contracts that rely on public data sources, as these would defeat the purpose of having a private blockchain.
However, there are many Ethereum applications that can be adapted to run on Quorum’s private and permissioned blockchain platform.