It does not always pay to design everything from ground up. Basing your product on a reference design or demo board can speed time to market. And on hobby projects using ready designs can help you so that you can concentrate using your time on the most interesting parts instead spending most of the time on the design yourself for all those part you consider not so interesting. Take advantage of open-source hardware article tells that open-source hardware offers an advanced start on your design. Open-source software complements open-source hardware. You may even want to share your improvements by making them open-source additions, as well. Article is available in both HTML and PDF version.