Software development is another professional skill that can be donated, but we consider it separately here because the products of this work, humanitarian software applications, merit a section independent of pro bono services. The work involved in coding and maintaining a software project is of significantly higher value (and personal investment) than the microwork tasks that are frequently used to represent participatory aid. Some of these efforts have been underway for years, and some involve communities of hundreds of remote volunteer developers. Some projects seek to help affected populations by improving the technology at the disposal of formal aid decisionmakers, while others seek to empower the affected population directly. Many serve both sets of users. Unsurprisingly, code travels well over long distances on the web. There is a rich history of open source projects designed and built by distributed networks of volunteers, including several notable projects in the participatory aid space, detailed below.