American Computer Science League
The American Computer Science League (ACSL) organizes computer programming and computer science contests for K–12 schools, organizations and local groups. The 2026–27 season is ACSL’s 49th year of continuous operation, and last year over 7,000 students from 21 countries on 6 continents took part in the regular season.
ACSL offers multiple divisions so that students of varying ages and abilities find an appropriate challenge. Each season is divided into four contests that test fundamental concepts in computer science. In the upper divisions, each contest also includes a problem to solve by programming in Python, C++ or Java.
ACSL is on the approved activities list of the National Association of Secondary School Principals (NASSP) and is an institutional member of the Computer Science Teachers Association (CSTA).
ACSL in Korea (KCSL)
KCSL (Korea Computer Science League) is the Pan-Asian region of ACSL serving students in Korea. KCSL runs ACSL’s computer science and programming contests for elementary, junior high and high school students, and holds them in person in Seoul and Jeju.
Students in Korea compete in the same contests as ACSL participants around the world, and the strongest performers are invited to the ACSL Finals.