The LearningOnline Network with CAPA (LON-CAPA) is an open-source freeware distributed learning content and course management system, which was developed with a special focus on both formative and summative assessment in large-enrollment science and math courses. As course sizes grow, communication between learners and educators during the semester frequently becomes a one-way street: presentation-style delivery of content to an anonymous mass of students. Eventually, there is an exam, but the feedback on learning progress comes when it is already too late, both for the learners and the educators. This seminar describes scalable solutions for continual formative assessment of learning progress, with a particular focus on large-enrollment physics courses. Strategies for computer-facilitated mastery-based homework and Just-in-Time teaching are presented. In addition, LON-CAPA establishes a content sharing network of currently over 35 institutions of higher education and an equal number of schools, allowing participating instructors to assemble modular content, including assessments, from the shared resource pool of currently around 150,000 resources. The seminar will be followed by a free hands-on workshop for anyone interested in learning more about LON-CAPA. (If interested in the workshop, please e-mail alan.denton@ndsu.edu so that we can create a trial account.)