Much of the free stuff you find on this page is shared in the form of instructional video or files available for download from GitHub or this website. On GitHub SKAARHOJ Open Engineering you will find a lot of printed circuit board designs (PCBs) and Arduino-compatible libraries for free. In return, we only ask you to respect the license terms which on the most fundamental level says that you must credit us visibly when you use our free technologies. Money is not everything and while we can help you with open source hardware and software, maybe you can help us to become more known in the world. That should be a sweet deal for all. We have made a Q&A page about licensing which will help you to make us happy.