Stephen Shankland/CNET

BARCELONA, Spain -- Big changes are coming to Firefox OS over the next year as Mozilla moves the browser-based operating system away from its current Android-style functioning.

At the Mobile World Congress show here Sunday, the nonprofit organization showed what's in store for its mobile OS. Much of it's about the interface changes -- notifications, task switching, app discovery, search.

"With the new model, we're really simplifying and making what we think is the ultimate browsing experience," Josh Carpenter, the user experience leader for Firefox OS, said at a press event. Browsing on Firefox OS means a lot more than just opening Web pages: Because all apps are built with Web technology, Mozilla counts anything on a Firefox OS phone as browsing.

Swiping from the edges, as in Windows 8 touch-screen devices, becomes key in the new operating system.

The top of a page shows a small strip of text that tells a user what app or Web site is on the screen. But swiping down a little opens that text box into an input field where a person can type search terms. That leads to searches on the Web, apps on the phone, or content within the apps -- it's all Web content to Firefox, so the boundaries between "the Web" and "native apps" are very blurry.

Firefox OS's new search-and-launch mechanism is a key change, one designed to get people do away with the app store hurdle of installing apps before you can use them.

"I want to get rid of the install button. 'Install' should be just 'open,'" Carpenter said.

Pulling down farther from the top invokes a task-switcher. Gone is the Android-esque notification screen.

Well, not gone exactly -- moved. The notification screen now is at the bottom, reached by swiping upward.

Swiping left or right from either edge on the side of the phone will switch from one app to another. The idea is to be more fluid, with easy switching among open apps, Carpenter said.

And under the covers, things should work better, too.

First, Mozilla has completely rewritten its software for controlling panning and scrolling when a person slides a finger around on the screen. The new approach is much smoother, which is crucial, Carpenter said.

"Responsiveness is the single most important important factor that determines whether a person likes a product," he said. People prefer responsive panning to a beautiful appearance, he said.

Second, Firefox OS will follow other operating systems in trying to improve typing accuracy by predicting what letter will come next and making the tap target for that letter invisibly larger.