A license is a piece of legal text accompanying information that one has to agree to before they are allowed to use said information.

The existence of licenses on digitally copiable information is absurd and should be eliminated.

Free License

A free license gives its user the freedom to:

  1. Use the work for any purpose
  2. Study it
  3. Share it, even commercially
  4. Modify it and share modifications, even commercially

Public Domain

A work in the public domain has none or expired copyright. Anyone is permitted to do anything they want with these works without restriction. It is not defined by every country's law.

Creative Commons Public Domain Mark (PDM) is a tag used to mark works already in the public domain. It is not a license or waiver and has no legal implications.


The CC0 License is a waiver (similar to a license) of copyright, created by Creative Commons, that can be used to dedicate one's work to the public domain. Unlike a license, a waiver such as this effectively removes the author's copyright. By using CC0, the author willingly gives up their own copyright so that the work will no longer be owned by anyone. CC0 also waives "neighboring rights", and also contains a fallback license in case waiving copyright isn't possible in a certain country. UFWiki is licensed under CC0.

CC0 is recommended for both programs and other art. For programs , additional waivers of patents should be added as CC0 doesn't deal with them.

Other similarly permissive licenses: MIT, MIT-0, Unlicense, 0BSD, zlib

CC0 Legal Code

CC0 Logo, CC-PDM Logo

Searches: Archive, Wikimedia Commons

Images: SkitterPhoto, OpenClipArt, BurningWell, Floyd Whitmore Photos, Duion

List of PD image resources

Other: Project Gutenberg (books/texts), Wikisource (books/texts), PDSounds(sounds), Librivox (audiobooks), OpenGameArt (different dev materials, mix of licenses),