Product design firm ZURB, the creator of tools like Notable and Verify, has just released Foundation 4, the latest iteration of its open-source, front-end, responsive framework, which serves as an alternative to frameworks like Bootstrap.

With this release, ZURB touts that its code-base has been “completely rewritten [to be] mobile-first.”

Clearly, placing emphasis on mobile devices is incredibly important, but ZURB shares that it is doing more than just considering smartphones: “Typically, designers create from the desktop-first perspective, then consider how their mobile design fits with the desktop design.” Instead, ZURB wants Foundation 4 to reverse that thinking by encouraging designers to create the mobile experience first. ZURB isn’t the first to think this way, but it’s an important move nonetheless.

In rare situations, such as when you’re designing Web apps for specific use-cases that call for larger screens, mobile-first isn’t the best frame of mind. Most of the time, however, sites should always look great across devices, because that’s how countless people access the Web. Starting your design process with a mobile layout is one way to make that happen.

Interestingly, ZURB has decided to ditch traditional jQuery for Zepto, a similar but more minimal JavaScript library, to “ensure that pages load quickly and efficiently given our mobile focus.” The company tells us it has also added “more mix-ins and placeholder classes.”

Today’s news follows ZURB’s recent acquisition of design community Forrst, and comes more than eight months after ZURB released Foundation 3. Check out the new release via the link below.

➤ Foundation 4

Edit: We originally shared an incorrect download figure, and have removed it from the post.