Harvard is not on a quarter system, Fall and Spring semesters are about 15 weeks long. For students who already have some programming experience, there are many

Harvard is not on a quarter system, Fall and Spring semesters are about 15 weeks long. For students who already have some programming experience, there are many opportunities to challenge themselves in the problem sets and especially the final project. As for the t-shirt, CS50 has one of the largest enrollments and Malan puts a lot of effort into making it fun, engaging, encouraging, and fostering a sense of community. Out of such a large enrollment at a liberal arts college, of course many will not take other CS course, but the course has definitely contributed to an increase in the number of students declaring CS as their major (what Harvard calls a "concentration").