Random Hacks of Kindness (RHoK) is an annual event organized and run by volunteers around the world.
TheRHoK's fourth edition takes place simultaneously in 21+ world cities. The two-day event brings together around 4000 computer programmers but also "engineers, designers, web experts, project managers and other tech-savvy do-gooders, as well as subject matter experts in areas as diverse as disaster risk management, climate change, water, healthcare and human rights".
TheRHoK is a joint initiative ofGoogle, Microsoft, Yahoo!, HP, NASA and the World Bank.