Many open-source bitcoin paper wallet softwares are available on github with their complete documentation, licenses, and copyright notes. If you are planning to recreate any of the bitcoin paper wallet github projects, or you want to use some of their functionalities in your own project, you need to take care of the licenses and copyright associated with the project. Read complete documentation of the project first before using it in your project. If the project is open-source and there is no restriction to use from the developer or from the company, then you can use that project.
This software of bitaddress.org is available on github under the MIT License Copyright to bitaddress.org. MIT License puts very limited restrictions on the reuse of the software.