I haven’t seen possibility to select a theme based on other framework than bootstrap. Will my theme be rejected because of using i.e.: foundation ver 4.0 or there is no restriction about that?
Of course not, you can build your own if you want.
The problem is, Foundation 4 doesn’t support IE8, and IE8 compatibility is still mandatory requirement on ThemeForest this day… There are some solutions for this, don’t forget to test your Foundation 4 theme on IE8 before you release it here…
I used it for my theme and it was approved. I wonder how much will IE8 last until support falls for it.