There is a wide variety of open source type of licenses out there. I’ll use this post to give a description of most of them. I don’t have time right this second to make this list, but this post is here as a mental note for me to come back and add a list later. Open source is NOT the same as public domain, although there are some similarities. Also, works of art created from the public domain to NOT require that they have open source licenses or remain in the public domain. It is perfectly ok to create a derivitive art form from a true Public Domain source and use it in commercial ways that are copyrighted or trademarked.