firefox_logo-only_RGB-300dpiLast night, Mozilla attracted more than 700 journalists to its Firefox OS press conference: a sign that its open-web smartphone operating system is being taken seriously by the media.

And by operators, it seems. 18 of them have signed up to sell the first Firefox OS-powered phones later this year, including Telefonica, Deutsche Telekom, Sprint and Telecom Italia.

The devices, made by Alcatel, LG and ZTE with Huawei to follow, will include access to the Firefox Marketplace app store for HTML5 apps, with Facebook, EA, Twitter, Time Out, Airbnb, Cut the Rope, Disney, MTV Brasil and SoundCloud all confirmed for inclusion. Oh, and Nokia is providing the mapping with its HERE application.

Brazil, Colombia, Hungary, Mexico, Montenegro, Poland, Serbia, Spain and Venezuela will be the first countries to get the new devices, hammering home the point that Spain aside, Firefox OS isn’t yet about challenging iOS and Android in the biggest Western markets.

Demos at the press conference showed a neat, usable operating system following the grids-of-icons pattern laid down by existing smartphones.

Mozilla was keen to stress the ease with which developers can make apps for Firefox OS. “There is no new ecosystem,” said SVP of products Jay Sullivan.

“If you’re building for the web today, and most developers are building beautiful touch-friendly mobile websites to work in modern browsers… If you are building that, you are building a Firefox OS app. You may just not know it yet.”

Sullivan also attacked claims that HTML5 apps can’t do offline running or storage, and promised that the Firefox Marketplace won’t be the only app store available for Mozilla-powered devices.

“I expect many marketplaces to flourish,” he said. “Some may be network operators, some may be verticals – you can imagine a games marketplace. And developers can distribute their apps direct to users with whatever business model they want.”

Sullivan also showed an impressive new feature linking apps and search, where people might search for ‘Skyfall’ on their Firefox OS phone, and be shown a screen of relevant apps (e.g. IMDB, Netflix…) which they can use once, or save to their phones for future repeated use.

“Think of it as single-use applications with the option to keep them more permanently,” said Sullivan.

There were clunking moments at the event though, as Mozilla and its partners drove home the advantages of openness.

CEO Gary Kovacs talked about the mobile internet being “unnaturally controlled by a few parties” and promised that Firefox OS would “free mobile” from the “broken model” of platform owners approving “every piece of content that you and I, or 6bn people, want to view and engage with”.

Neither Apple nor Google demands approval of the websites that people access through their iOS and Android browsers, of course, but if there’s a “broken model” in the smartphone world currently, it’s just as much about the operators, who’ve been unceremoniously shunted out of the apps ecosystem in recent years to become mere bandwidth providers.

So, last night you had the spectacle of America Movil’s Marco Quatorze saying “I believe this is the beginning of the end of the walled gardens” – operators invented walled gardens on mobile with their proto-App-Store portals back in the day, with the walls constructed to keep out the open web and small developers.

And you also had Telefonica chairman and CEO Cesar Alierta hailing Firefox OS as “a major step to bring balance back to the telco sector”, saying with a straight face that the smartphone market “is currently moving backwards”, and that this is “not good for us, it’s not good for the developers, and the OEMs. But the most important thing: it is not good for the customers”.

Visions of mobile users rioting because of the lack of openness in their iOS and Android smartphones – sold in bulk by those very same operators – aren’t exactly realistic.

But Mozilla’s vision of Firefox OS as the first smartphone OS hundreds of millions (billions, even) of people in developing markets will encounter is much more compelling. This OS may have wings.