I was playing with the Hermitian curve $y^q + y = x^{q+1}$ over the field $GF(q^2)$ and chanced upon the following (non Abelian) group law on the points of the affine curve:

$(a,b) * (c,d) = (a+c,b+d+ac^q)$.

Over $GF(q^2)$ the group has $q^3$ points, the identity is $(0,0)$ and 
the inverse of $(a,b)$ is $(-a,b^q)$.

So my question is whether this is known. I could not find a reference.
If you haven't seen this before and if you're interested in seeing how I found this group law, just shoot me an email.

Thanks for your time.
Best,
Hiren