Quadruino, an Arduino QuadCore !!!

I have that program, too. I think it just moved up in my "need to learn" queue.

I like it. They don't have the fanbase out there that eagle does so I wound up having to make more than a few component packages myself, but it's easy to get up an running on.

I've since upgraded so I can panelize multiple boards onto a single run and was exceeding the pin limit, but the free or Non-profit versions are great.