http://arstechnica.com/tech-policy/2015 ... ht-battle/
I'm not sure what to think of this.

But this isn't completely settled yet, hopefully re-implementing / reusing other people's APIs while appropriately crediting the API's creator(s) will at least be considered fair use.
(mozillaZine: http://forums.mozillazine.org/viewtopic ... &t=2944175)