Our SIMIODE digital textbook is authored by the distinguished teacher and writer, Dr. Kurt Bryan, Rose-Hulman Institute of Technology, Terre Haute IN USA. This text is designed for a first course in differential equations for undergraduate mathematics, engineering, and science majors, and is suitable as a stand-alone textbook. It is a first of a kind text using a modeling first and throughout approach to motivate and teach differential equations. We would like to introduce you to an exciting project: SIMIODE - Systemic Initiative for Modeling Investigations and Opportunities with Differential Equations. This YouTube channel is where we place our growing set of videos in support of SIMIODE (https://www.youtube.com/c/SIMIODE) SIMIODE is about teaching differential equations using modeling and technology upfront and throughout the learning process. Learn more at our dynamic website, https://www.simiode.org, where we offer a community in which colleagues can communicate, collaborate, publish, teach, explore, contribute, etc. We are building a complete environment for teachers and learners -- communication, groups across and intra/inter campus projects for students and teachers, models, data, videos. Features: - Modeling first approach throughout - Links to many SIMIODE Modeling Scenarios and other sources - Fresh narrative on the rationale for studying differential equations - Practice problems and questions, many with solutions - Projects in each section - Modeling threads through the text - Extra sections and appendices, e.g., control theory, linear algebra, circuits