Just ahead of the start of the Mobile World Congress in Barcelona, Mozilla today announced a number of new Firefox OS smartphones from partners like ZTE, Huawei and Alcatel, as well as a $25 reference design from Spreadtrum.

When Mozilla announced its plans to build a phone operating system a few years ago, most pundits didn’t expect much would come of this. But in 2013, it launched phones with a number of partners and made inroads in many developing countries. The three available Firefox OS phones are now available in 15 different markets and through four network operators.

Most of the sales are happening in Latin America and Eastern Europe today, but looking to 2014, Mozilla expects to get into markets in Asia and Africa as well and to expand in Latin America and Europe with planned launches in Argentina, Costa Rica, Croatia, Panama, the Czech Republic, Macedonia and other countries.

As Mozilla’s COO Jay Sullivan reminded me last week, the goal behind Firefox OS remains to be an affordable solution for people who are coming online for the first time in emerging markets. The organization wants to stay true to this mission, but this year, it’s going to move both closer to the low-end, with the $25 reference design it expects some OEMs to manufacturer, and to the mid-range, with some of the new phones launching at MWC.

ZTE will show both the new Open C and Open II dual-core Firefox OS phones at MWC, for example. Huawei is announcing its first Firefox OS phone – the Huawei Y300 and Alcatel ONETOUCH is launching a range of new phones under the “Fire” brand, as well as a concept for a 7″ Firefox OS tablet. Alcatel’s phone span the gamut from a basic 3.5″ dual-core HVGA phone to the 4G-enabled Fire S with a 4.5″ qHD display, a quad-core processor, LTE support and 8 megapixel 1080p camera. As far as I can tell, that’s the most powerful Firefox OS phone announced so far.

At CES, Panasonic showed off a Firefox OS-based TV and Sullivan expects that others will take the open-source operating system and use it for similar applications. Mozilla itself doesn’t have any plans to expand its efforts besides mobile. “We focused on this low-end market,” he told me, “but then many manufacturers got interested in using Firefox OS for other applications as well.” After all, the code is open source, so manufacturers who want to take it can customize if for their needs.

Mozilla hopes that as more phones come on the market and the ecosystem expands, developers will also get on board. Thanks to its support for ASM.js, the organization hopes that more game developers will also take a look at the platform, which is fully based on HTML5 and JavaScript.

In the early days, it was easy to laugh about Firefox OS. With this new range of partners and upcoming launches in a wide range of new markets, however, Mozilla’s chances at making a dent in the smartphone ecosystem in developing countries are starting to look much better than ever before. It’s easy to laugh it off, but if anything, it’s a worthwhile mission to pursue, and given its status as a nonprofit, Mozilla can experiment in this field more openly than its competitors.