It looks amazing, but also difficult to understand how it exactly works. Anyway, i notice they have really unique licensing option on their source code.
This software is licensed under [Apache 2.0](LICENSE-APACHE) or
[MIT](LICENSE-MIT), at your option.
Some files retain their own copyright notice, however, for full authorship
information, see version control history.
Except as otherwise noted in individual files, all files in this repository are
licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
http://www.apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
http://opensource.org/licenses/MIT>, at your option.
You may not use, copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of this software or any files in this repository except in
accordance with one or both of these licenses.
I've seen some project let you choose between open source license or propriety license (with paid support or feature), but this one is entirely different.
