Foundation framer, Bootstrap builder and Responsive Site Designer all have similar interfaces to one another. RSD gives you a choice of the foundation, bootstrap and its own frameworks to choose from. Foundation is a mobile-first framework created by
zurb. Bootstrap is a desktop-first framework developed by, I believe, Twitter. The difference is simply whether you choose to create your mobile version first and then your larger versions, or your desktop version first and then your mobile versions. None of them resemble Netobjects Fusion. Nothing does.