These are extra components from the Fornjot repository, that are no longer actively maintained.
Fornjot's goal was to create a next-generation, code-first CAD application. This goal has changed (see A New Direction), and these components no longer fit the new scope.
If you want to fix an issue, or update these components to use the latest version of Fornjot proper, your pull request is always welcome! However, more ambitious work, like substantial feature additions or other larger changes, are more suited for a new project. Fork at will!
This project is open source, licensed under the terms of the Zero Clause BSD License (0BSD, for short). This basically means you can do anything with it, without any restrictions, but you can't hold the authors liable for problems.
See LICENSE.md for full details.