Explore the challenges and solutions in developing open computer science education resources for schools in this 53-minute conference talk from linux.conf.au. Delve into the experiences of creating two online open resources at the University of Canterbury: CS Unplugged and CS Field Guide. Learn about the design principles used and the obstacles faced in making these materials relevant across different cultures, curricula, and languages. Gain insights into supporting teachers with easily deployable teaching materials for Computational Thinking and related topics appearing in school curricula worldwide. Discover how open-source principles are being applied to address barriers in CS education adoption.