_**Editor’s note**: This article is the second piece in our new series introducing new, useful and freely available tools and techniques presented and released by active members of the Web design community (the first article covered [PrefixFree](https://www.smashingmagazine.com/2011/10/12/prefixfree-break-free-from-css-prefix-hell/), a new tool be Lea Verou). ZURB are well-known for their wireframing and prototyping tools and in this post they present their recent tool,_ Foundation, _a framework to help you build prototypes and production code that’s truly responsive._ “Foundation”)](https://www.smashingmagazine.com/2011/10/25/rapid-prototyping-for-any-device-with-foundation/) You’ve probably already heard about responsive design, which is website design that responds to the device constraints of the person viewing it. It’s a hot topic right now, and with good reason: alternative devices outsell desktop PCs 4 to 1 already, and within three years more Internet traffic in the US will go through mobile devices than through laptops or desktops. All of this is forcing a convergence on what Jeremy Keith calls the “one Web”: a single Web that doesn’t care what device you’re on, how you’re viewing content or how you’re interacting with it.