Welcome to The SuperCollider Book code repository!
You can read more about the book here
SuperCollider is under GNU GPL 3 and so is all the code here.
The folders contain chapter by chapter breakdowns of code, which may include updates to cope with changes in SuperCollider or book errata. They also include extra files like compositions and classes, and bonus materials.
If you are looking for code examples for the first edition, please use the first-edition branch and the v1.x tags. For the second edition use master and v2.x tags.
Have fun!