Soon I am going to release my first shield into the wild. I would like it to place it under similar license conditions as Arduino itself. However I failed to clearly determine the exact license terms for Arduino related things. I found parts to be under several different versions of LGPL, GPL, CC and some stuff even in the public domain. The FAQ was not helpful either. Some look like historical remainders, others just strange.
Is there any overview / statement of which license is applied under which circumstances and why? Or at least some comment what is used for the newest stuff?