Guix

The REUSE tool helps you achieve and confirm license compliance with the REUSE specification, a set of recommendations for licensing Free Software projects. REUSE makes it easy to declare the licenses under which your works are released, especially when reusing software from different projects released under different licenses. It avoids reliance on fuzzy heuristicts and allows both legal experts and computers to understand how your project is licensed. This allows generating a "bill of materials" for software.

This tool downloads full license texts, adds copyright and license information to file headers, and contains a linter to identify problems. There are other tools that have a lot more features and functionality surrounding the analysis and inspection of copyright and licenses in software projects. This one is designed to be simple.