The main part of this project, material-yewi is licensed under GPLv3. As a contributor to free software, I am opposed to companies using the work commercially, even with proper attribution. If you are a smaller organization and want to use this project or parts of it and can not comply with the terms of GPL, raise an issue or email me.
If you want to contribute to this project, please also tell me your opinion about the license as I might want to change it in the future to be less restrictive. At the same time I don't want past contributors to feel cut out then.
Also keep in mind that the GPL only covers material-yewi and not the rest of the modules, such as yew-styles and the documentation.