Firefox OS makes its debut (pictures)

Firefox OS will look familiar to smartphone users. Here's the app screen shown on a ZTE Open.

Cut the Rope, a classic mobile app that's made its way to many different operating systems, works on Firefox OS. It's shown here on a Geeksphone Peak developer phone.

The gallery app on Firefox OS presents photos as an array of thumbnails that scrolls vertically. To do something with a photo, like share it or edit it, you must tap on it to open it.

Firefox OS's gallery app lets you crop photos, apply some basic color filters, adjust contrast, and share photos with a system resembling Android's "intents." That lets you pick a variety of destinations registered to handle photos.

Firefox OS's phone app includes tabs for a dialing keypad, an address book to find contacts, and a recent call list. This is on the Geeksphone Keon, a lower-end developer-oriented phone.

Firefox OS includes a clock app, unsurprisingly, which you can use to set alarms. The Geeksphone Peak shown here has a fairly sharp 4.3-inch QHD screen.

Firefox OS's camera app in action on the Geeksphone Peak. The phone has an 8MP back-facing camera and a 2MP front-facing camera.

Powered by Firefox OS, the ZTE Open naturally includes the Mozilla browser, too.

The ZTE Open with first stage of the two-stage Firefox OS unlock screen. Pulling up from the bottom of the screen then reveals an option to unlock the phone or to launch the camera.

Firefox OS's contacts app lets you import contacts from Facebook. Mozilla plans to add support for Web-based mail systems such as Yahoo Mail, Gmail, and Hotmail later.

A long press on the home button invokes the task switcher. This view shows one rough edge on the experience: the horizontally oriented Cut the Rope app doesn't fit well in the vertically oriented thumbnail.

The opening screen of Firefox OS running on a Geeksphone Keon.

The Geeksphone Peak, designed for developers, is one of the first phones to sport Firefox OS. It's got a dual-core Snapdragon S4 processor running at 1.2GHz.

Firefox OS, shown here on the ZTE Open, has a gallery app, but if you want to share photos, you have to do so one at a time by opening it first.

The ZTE Open feature a traditional phone dialer, with tabs along the bottom to access recent calls, contacts, and the dialpad.