Mozilla wants its HTML5-based Firefox OS to succeed, and to do that they need developers. That demand may explain why the open-source non-profit organization is giving a number of GeeksPhone Keon smartphones to developers for free.

But there is a catch.

In order to qualify for a free phone, developers will have to pitch an application that'll run on Firefox OS to Mozilla. If the pitch is accepted, the phone is shipped. The program, according to Mozilla, ends at the end of May or when Mozilla runs out of phones to give away.

"When Firefox OS phones become available to consumer in select locales this summer, you'll have an opportunity that only comes around once - a first-mover advantage in Firefox Marketplace," Mozilla's Havi Hoffman wrote in a blog post announcing the program.

GeeksPhone's Keon is one of two phones to first run Firefox OS. The other, the Peak, is also developed by GeeksPhone and is a slightly higher-end handset.

The Keon features a 1-GHz Qualcomm Snapdragon S1, 3.5-inch touch-screen display, a 3-megapixel camera, 4GB storage, 512 MB of RAM, a 2G Edge antenna, GPS, Wi-Fi, Bluetooth and MicroUSB port.

The Peak features a 1.2GHz Qualcomm Snapdragon S4, a larger 4.3-inch HD screen, an 8-megapixel rear-facing camera and a 2-megapixel front-facing camera, 4GB of storage, 512MB of RAM and a variety of other features shared with the Keon.

But why test Firefox OS on sub-par phones?

Well, that's because Firefox OS is targeted at emerging and low-end markets, and will first launch to users in Latin America and Eastern Europe.

But Firefox OS could end up on high-end phones as well. Mozilla is working with high-end phone manufacturers like Sony, LG and ZTE to craft handsets for Firefox OS. Mozilla hopes its open source platform will become the third major mobile OS to compete with Android and iOS.

"The low-end entry point devices are good [sic] point to enter the market," said Li Gong, Mozilla's senior vice president for mobile devices, according to Computerworld. "But that doesn't mean we can't scale up or we don't want to scale. We do want to scale up."

Both the Keon and the Peak are available at GeeksPhone's website, and both can be shipped globally.