They are copyrighted. They are free software. curl's is distributed under a MIT/X [1]. It is not copyleft. wget is distributed under the GPLv3 [2]. It is a copy

They are copyrighted. They are free software. curl's is distributed under a MIT/X [1]. It is not copyleft. wget is distributed under the GPLv3 [2]. It is a copyleft license. Both licenses' legal basis is copyright law, and the copyrights held by the tool's authors. All of this probably does not apply to shell aliases anyway... [1] https://curl.haxx.se/docs/copyright.html https://curl.haxx.se/docs/copyright.html [2] http://git.savannah.gnu.org/cgit/wget.git/tree/README http://git.savannah.gnu.org/cgit/wget.git/tree/README