The code in the listed paths is licensed under MIT License:

* include/Sierra
* src/Sierra

Any other code is licensed under the license hosen by its creator:

* Makefile template by Arash Partow: MIT License
* TinyJS by Gordon Williams and Armin Diedering: under its own license present in its respectives folders
* Catch framework: Boost License 1.0

Anything else is left licenseless unless specified elsewhere.