Everything on this site is under NBPL.
See the link to NBPL on the frontpage for the newest version.
Or if you're a bit lazy then just click here.
If you're publisher or whatevs really insist on getting sum "proper"
All of the drawings, screenshots and screencasts that are made by me are public domain under CC0
All of the text written by me that is not code is also public domain under CC0
All code is can be redistributed under GNU General Public License 3 or any later version of it (GPLv3+).
The GPL can be found at GNU.org