The Arm Confidential Compute Architecture (CCA) is an extension of the Armv9 architecture designed to provide confidential computing in standardised and scalable way. CCA builds on existing principles built for TrustZone and virtualization to create a scalable and secure solution. CCA places requirements on hardware and firmware, which together provide the trusted computing base for a new class of secure execution environment that we call a Realm. Trusted Firmware is the key community project that provides a reference implementation of open source Secure firmware for Arm-based processors. This talk briefly introduce Arm CCA and illustrate how Arm plans to develop and enable it in the open by leveraging the community effort that drives Trusted Firmware as open-source project.