Osmosis is a web- and mobile-based learning platform that helps clinicians and students better discover, learn, and retain knowledge. This is accomplished through a combination of cognitive techniques, including spaced repetition, testing effect, social learning, and contextual cues, with technologies such as a machine learning-powered resource recommendation engine. Osmosis has shown significant user engagement with over 20,000 medical and other clinical students signed up internationally and six pilot schools using the platform. It is also creating the largest bank of open medical educational resources, starting with clinical questions. Osmosis has partnered with organizations such as the American College of Physicians, received top awards including the Penn-Milken Education Competition Grand Prize, and earned a Pioneer Grant from the Robert Wood Johnson Foundation.