Stay on Top of Emerging Technology Trends Get updates impacting your industry from our GigaOm Research Community

The developer test phones for Firefox OS are now on sale. They’re being produced by Geeksphone, a small Spanish outfit that used to make Android handsets for true open-source cognoscenti and that is now backing Mozilla’s operating system as the way forward.

Geeksphone is far from the only company pushing Firefox OS – operators seem especially keen, largely because they want to shake up the Google(s goog)/Apple(s aapl) smartphone duopoly. However, it is the only firm thus far to start selling devices using the operating system (ZTE will also sell Firefox OS phones from around the middle of the year).

Firefox OS’s big differentiator is its treatment of HTML5 web apps as native, which means apps built for this platform should run on other smartphone platforms too.

“With early access to hardware, developers can test the capabilities of Firefox OS in a real environment with a mobile network and true hardware characteristics like the accelerometer and camera that are not easily tested on the Firefox OS Simulator,” Stormy Peters, head of developer engagement at Mozilla, said in a blog post. “Plus, new hardware is fun to play with!”

The two phones – the Keon and the Peak – can be shipped anywhere in the world. The Keon, which costs €91 ($119) plus taxes and which already appears to be sold out, is representative of the kind of hardware that will ship to Firefox OS customers first: 3.5-inch screen, entry-level Qualcomm(s qcom) 1GHz processor and a 3MP camera. This very much targets the low end of the market in regions such as South-East Asia and South America.

The €149 ($194) Peak is more forward-looking in terms of Firefox OS, although the specs will be familiar to those who have scouted out current low-to-mid-range Android handsets: 4.3-inch screen, dual-core Qualcomm 1.2GHz processor and an 8MP camera. Both devices feature 512MB of RAM, 4GB of ROM, MicroSD support and the various sensors you’d expect in a modern smartphone.