Mozilla has announced an audacious project to build an open source smartphone and tablet operating system to rival the increasingly cosy three-way domination of Android, Apple’s iPhone and Windows Phone.

Under the name of Boot to Gecko (B2G), the new OS will take the Gecko HTML rendering engine of Mozilla’s Firefox browser and Thunderbird email client and build around it a wholly open source project capable of running atop Android-compatible hardware thanks to re-use of a few nuggets of low-level code from that OS.

The B2G project is still at a very early stage but the outline of something complex and unusual can be discerned form the blog comments that announced it.

Its foundation will be to use open web standards rather than “single-vendor stacks”, risky given the immaturity of that environment, but consistent with Mozilla’s open web vision.

The development team announced four areas that are needed to get Boot to Gecko off the ground, including new APIs to tie the underlying Android hardware layer to software for interfaces such as telephony, storage, cameras, and networking comms. Security design is also a key issue; source code resulting from all development will be released in real time.

“This project is in its infancy; some pieces of it are only captured in our heads today, others aren’t fully explored. We’re talking about it now because we want expertise from all over Mozilla - and from people who aren’t yet part of Mozilla - to inform and build the project we’re outlining here,” announced the Mozilla project team.

As is the nature of open source, the exact direction of future development will depend to some extent on those who contribute to it.

Whatever B2G turns into, perhaps its biggest challenge isn’t to Android itself but to Google’s model for developing that operating system, which sees source code released at the company leisure in a way that some believe has fragmented application development across different versions. The pointed release of source code as development proceeds is a backhanded reference to frustrations at Google’s approach.

“We want to do Boot to Gecko the way we think open source should be done. In the open, from day 1, for everyone to see and participate,” said Mozilla project leader, Andreas Gal.

Boot to Gecko is also a way of proposing not just a market alternative to established proprietary mobile operating systems, but a different direction altogether, one centred on web applications.

It has some similarities to Google’s own ChromeOS – in other words the belief that web applications will be the foundation of future operating systems – and could turn into a slightly different version of the same thing minus the association with a single commercial interest.

Boot to Gecko will attract a lot of interest but hurdles remain. The pace of development will be watched very closely on the gitub project repository.