MetroHacks, run by high-school students to host high-school hackathons in the Boston area, will host MetroHacks III, a free, 24-hour event for ages 13-18 at the Harvard Student Organization Center, May 19-20. There will be speakers, free food, workshops, games, and prizes. Mentors and workshop leaders can help with projects and with learning Python, iOS app development, HTML/CSS, and more. Beginners as well as experienced coders are invited to register by May 1.