Open source in the Internet of Things

91% of IoT developers use open source technology in their projects. Open source is a major factor in the Internet of Things. In this report, we examine the state of the art in how and why IoT developers use open source software, open source hardware, and open data. How mainstream is open source in IoT? Is it just for hobbyists and idealists, or is there more to it than that? Which developer demographics use open source and why? How can I make sense of the hundreds of open source, open hardware, and open data licenses that are out there? Should your project be open or closed? How can you use open source to achieve commercial success?