Welcome to the #Huckathon! Our goal is to map previously un-mapped areas of the world in order to help address chronic humanitarian crises. In this case, we are mapping Northern Uganda in order to allow the provision of prosthetic limbs to the many thousands of people who lost arms and legs during the 30-year conflict that devastated the region. Volunteers fill in blanks on the map using aerial photographs and we make the results into freely available digital and paper maps! In addition to the delivery of prosthetic limbs, our free maps have also been used for a variety of other purposes, including the installation of Internet connections for 23 health centres and more than 200 schools in the region. So come and have a go: no experience is required and a few minutes of your time can make a real difference to people’s lives!