CS50

CS50 is Harvard University's introductory course in computer science. Taught by professor David J. Malan, it is offered on campus through Harvard College and the Harvard Extension School, and online worldwide via edX as CS50x. The course emphasizes problem solving, programming, and software engineering, and is known for its rigorous problem sets and active, global community.

Curriculum centers on both theory and practice. It begins with C as the first language, then introduces Python, SQL, and web development using HTML, CSS, and JavaScript. Core topics include algorithms, data structures, memory management, and software design. Assessment is delivered through a sequence of challenging problem sets and a final project, typically developed in the CS50 IDE and submitted for evaluation.

Format and delivery: The on-campus offering includes lectures and sections led by teaching fellows; the online edition on edX provides a self-paced track with scheduled content. The course is noted for Malan's engaging lectures, walkthroughs, and a strong emphasis on hands-on learning and collaboration among students.

Impact and reach: CS50 has become one of Harvard's most popular courses and has a substantial international footprint. It has spawned related courses such as CS50's Introduction to Game Development and CS50's AI with Python, as well as a large alumni network and community events. The program has influenced introductory CS pedagogy by prioritizing accessible, project-based learning.

Prerequisites and accessibility: CS50 is designed for beginners; no prior programming experience is required, though comfort with problem solving helps. Materials are freely available online, and edX offers an optional certificate for a fee upon completion.