The first two developer smartphones running Mozilla’s upstart Firefox OS went on sale Tuesday morning and then quickly sold out.

Manufactured and sold by Spain-based Geeksphone, the new devices were both described as “developer preview” handsets intended for app makers interested in building and testing applications for Firefox OS.
“The Firefox OS Developer Preview Geeksphone devices have development versions of Firefox OS and are unlocked so that developers can use them wherever they are in the world and they are updated regularly with the latest Firefox OS build,” explained Stormy Peters, Mozilla’s director of websites and developer engagement, in a Monday blog post.
Down for maintenance
Even before 6:00 a.m. PDT on Tuesday, however, the devices were reportedly already gone. As I write this story just a few hours later, the Geeksphone store site has been intermittently down for maintenance.
Even in their early form, it appears there’s no shortage of demand for these new devices.

Firefox OS is a Linux-based and open source mobile operating system that focuses on the Web much the way Google’s Chrome OS does. Taking the OS’s openness yet another step further, however, Firefox OS apps are built using basic Web technologies such as HTML, CSS and JavaScript, thus enabling pretty much anyone who has ever built a Web page to create one.
The two devices put on sale today were the $194 Peak, featuring a Qualcomm 8225 dual-core 1.2GHz processor, a 4.3-inch display, and front and rear cameras, and the $119 Keon, a smaller device that features a Qualcomm 1GHz Cortex-A5 processor, a 3.5-inch display, and 512MB of RAM.
More devices due this summer

Sony, Huawei, and LG are among the many other phone makers Mozilla has teamed up with to create some of the first consumer devices running Firefox OS, which are expected to start showing up this summer. Most will offer specs similar to those of the lower-end Keon, Peters noted.
How well this open OS will fare against the likes of iOS and Linux-based Android remains to be seen, of course, but the quick sell-out today is certainly a positive indication.
In the meantime, those interested can use the browser-based Firefox OS Simulator to view and test mobile apps on the desktop or even install Firefox OS on their own hardware.