Just curious, is there a reason you chose GD over imlib2?
I've used both and I think I prefer imlib2 for flexibility and breadth, and there's already at least one imlib2 binding for PHP: http://pp.siedziba.pl/
Thanks, I'd seen so many language bindings for imlib2 (and, yes, gd) that I'd assumed it was an active project, but you're right that it's not. Also gd does a lot more than it used to.