Concert.js is released under the MIT License, as spelled out below. The terms of this license are very permissive and allow using Concert.js in any project, including commercial projects, as long as the copyright notice and MIT License text are retained. For more information on the MIT License, you may wish to view its Wikipedia entry.
Copyright © 2014-2020 Trajan McGill
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
The requestAnimationFrame.js shim distributed with Concert.js is not required for the use of Concert.js itself, but is supplied in case support is desired in your projects for extremely old browsers (roughly pre-2013, although some supported it earlier). This component is in the public domain and is freely usable in any way. See this web page for details.
Concert.js is released under the MIT License, as described in the section above.
This component, used in unmodified form here, bears the Apache License, Version 2.0.