Explore the exciting world of Open Instruction Set Architectures (ISAs) in this 42-minute conference talk from linux.conf.au 2021. Delve into the recent growth of RISC-V and OpenPOWER, examining their evolution from academic projects to serious contenders in commercial processor architectures. Learn about the expanding ecosystem of open source hardware designs, ranging from microcontrollers to server-class enterprise systems. Discover the latest developments in Open ISAs, including new extensions and specialized compute functions now seen in production systems. Gain insights into the relevance of Open ISAs to the broader open source community and understand their importance in maintaining viable libre computing alternatives amidst increasing consolidation in the closed CPU space.