Teacher learning to enact desirable yet knotty teaching practices is a complex challenge that requires innovative support. Most materials intended to support professional learning fall short and do not leverage the benefits of modern technologies to address historic barriers at school, district, and broader systemic levels. We provide a synthetic literature review of teacher learning, identify impediments, and suggest a new, technology-enabled approach to the co-design of teacher collaborative learning materials enabled by open technologies, a revolutionary mindset enabled by open technologies. We frame the Open Guidebook Approach (OGA) in terms of five values: collaboration, practicality, continuous improvement, accessibility, and adaptability. We illustrate OGA with an ongoing project, called "Making Meaning," to support teachers learning to enact equitable practices, drawing on concepts, indicators, and observation rubrics from the Classroom Assessment of Sociocultural Interactions. Supporting teachers to transform their teaching is our objective, OGA via open technologies is the innovative means, and Making Meaning illustrates our arguments. We conclude with recommendations and ongoing questions.