Short version for non-lawyers:

Ratelimit is dual-licensed under Apache 2.0 and MIT terms.


Longer version:

Copyrights in Ratelimit are retained by their contributors. No copyright
assignment is required to contribute to the Ratelimit project.

Some files include explicit copyright notices and/or license notices.
For full authorship information, see the version control history.

Except as otherwise noted (below and/or in individual files), Ratelimit is
licensed under the Apache License, Version 2.0 <LICENSE-APACHE> or
<http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
<LICENSE-MIT> or <http://opensource.org/licenses/MIT>, at your option.