The first thing entrepreneurs usually think about when dealing with public domain materials is text material, specifically books and reports. Most public domain dabblers already know that the US government has thousands of publications in the public domain and encourages the distribution of them, or that Project Gutenberg hosts thousands of free texts that can be used for product creation. But there's a whole treasure trove of delights you can find online and off in that copyright free world of public domain, including software, audio, film, and art. And yes, they can legally become part of your next product!
Read Lisa Preston's entire article Treasures in the Public Domain
Lisa Preston, Our Official Writing for Entrepreneurs Expert