Photograph of Henri Léon Lebesgue (1875-1941), who laid the groundwork for modern measure theory and remade the theory of integration. (Courtesy of The MacTutor History of Mathematics Archive, University of St. Andrews.)
MIT OpenCourseWare makes the materials used in the teaching of almost all of MIT's subjects available on the Web, free of charge. With more than 2,000 courses available, OCW is delivering on the promise of open sharing of knowledge.