The European Society of Radiology (ESR) initially developed the ESR e-Book as an open-access digital teaching resource aligned with the undergraduate European Training Curriculum for Radiology. Over time, this initiative evolved into Modern Radiology, a rebranded and expanded version that now serves not only medical students and educators but also residents and other healthcare professionals. Unlike traditional textbooks, Modern Radiology follows a visually engaging and succinct format, emphasising key concepts through annotated images, attention points, hyperlinks, and self-assessment sections. It complements case-based and interactive learning methods, providing a systematic foundation for radiology education. By continuously updating its content to reflect advancements in the field, Modern Radiology has been widely adopted by universities across Europe and beyond. Furthermore, several translations are in progress, ensuring its accessibility to a broader audience. KEY POINTS: Modern Radiology is an open-source, non-commercial teaching resource for undergraduate and postgraduate radiology teaching. It is a living document that follows the European Society of Radiology (ESR) Training Curriculum for Radiology. Its didactic and concise format facilitates the acquisition of basic knowledge and the preparation of interactive teaching and self-learning. It is widely used in universities across Europe and beyond, as well as by residents in training.