Cosmopolitan is released under the ISC license, which is a simplification of the MIT/BSD licenses made possible by the universal adoption of the Berne Convention.
Copyright 2020 Justine Alexandra Roberts Tunney Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies. THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
Cosmopolitan vendors third party components, which are licensed BSD, MIT, or Apache 2.0. There is a notice at the top of each source file documenting such licenses.
Furthermore, Cosmopolitan automates notice embeddings using the GNU
Assembler .ident directive. This means that by viewing
the content of linked binaries, you can see the transitive closure of
notices that apply to your work.
It also automates compliance. Notice licenses like ISC/MIT/BSD require that you distribute the notice along with your work. Since the linker automatically embeds them you can have sexy single-file distributables that are legally prim-and-proper with hardly any effort at all.