Actually, they don't. Any work you do is automatically restricted in its use. What open source licenses strive to do (to varying degrees, depending on license)

Actually, they don't. Any work you do is automatically restricted in its use. What open source licenses strive to do (to varying degrees, depending on license) is basically: * Reduce the risk for the person publishing the thing * Grant rights to the user of the thing * Restrict (or not) the ways in which the thing can be distributed to others About the closest to public domain you can get is probably something like this: http://creativecommons.org/about/cc0 http://creativecommons.org/about/cc0