I am not an attorney. None of this constitutes competent legal advice. None of it.
Free Software Foundation General Public License (GPL)
Version 2: Used for the Linux kernel and other older software
Version 3: More commonly used with newer software
"Permissive" Open Source License
Do what you will (within reason)
BSD License: "3-clause", "2-clause"
Other Licenses Of Note
Perl Artistic License
Attempts to abandon all copyright in the work
Perhaps not even legally viable
Many "licenses" of questionable utility try to simulate
Creative Commons provides super-permissive licenses crafted by actual attorneys: these are preferred
In particular, "CC-0" is as close to Public Domain as makes no difference, but enforceable