Mozilla's Firefox OS, originally known as Boot to Gecko, is going to attempt to become a key player in the highly competitive mobile market, which is currently dominated by Android and iOS.
It's still unclear how much of a success (or failure) Firefox OS will be, but here's 10 things you need to know about Mozilla's mobile offering.
1. Release date
The first handsets running the Firefox OS are likely to arrive in January 2013, with Telefonica revealing it will be launching its first device in Brazil sometime in the first quarter of the year.
Firefox OS devices will make it to the UK and US, with launch dates thought to be sometime in the second half of 2013.
To start with, handsets running Firefox OS will be aimed at the budget end of the market, so expect to see a raft of super cheap smartphones.
Telefonica has said that its first handset, which will go on sale in Brazil, will come in at sub $100 (around £65).
In the future Mozilla will look to get the Firefox OS onto mid and high-end handsets, but it's starting at the bottom.
3. Web-based HTML 5
4. Better than Android
Telefonica Chief Executive, Matthew Key has claimed that the Firefox OS will offer "a better budget experience than Android" – a big claim and something we'll put to the test when it arrives next year.
5. Easy app porting
Developers should be able to easily port their HTML 5 apps to the Firefox Mobile OS, which apparently will be quite a lot according to research by Telefonica, which found 75% of Google Play and Apple App Store apps are already written in HTML 5.
6. Social networking integration
Both Facebook and Twitter will be deeply integrated into the Firefox OS, allowing users to easily post updates, link contacts to profiles and keep up to date with all their friends.
7. Full Google Maps
Thanks to the HTML 5 base of Firefox OS, a click of the Google Maps app reveals the full blown version of the mapping software which you get on your computer - impressive.
8. Qualcomm power
All handsets which will run Firefox OS will sport Qualcomm processors, as Mozilla has done an exclusive deal with the chip maker.
9. Widget potential
Even though the demo of Firefox OS we were shown had iPhone-esque homescreens of apps, Mozilla isn't ruling out the inclusion of widgets on the mobile platform.
10. Simple, quick and efficient
What Firefox OS claims to offer is a simple, speedy and efficient user experience at the low end of the market, even on handsets running 600MHz processors.