Mozilla has started developing an official port of its Firefox Web browser for the Windows 8 Metro environment. They intend to deliver a fully functional version of the browser that will integrate with the Metro experience and offer a touch-friendly user interface.

The original plan for a Firefox Metro port was announced earlier this year when Mozilla published its 2012 strategy. The organization's plans for supporting Windows 8 were documented in the roadmap. Development on the port began this week, according to a blog entry published by Mozilla developer Brian Bondy.

Bondy described some of the technical details surrounding Metro browser development and explained how Mozilla intends to proceed with its implementation. The Metro environment imposes some strict technical limitations on developers, but Microsoft is making an exception for browser vendors.

The Windows 8 developer documentation says that "Metro style enabled desktop browsers" are a separate class of software that won't be subject to all of Metro's restrictions. This designation is intended for desktop Web browsers that have a separate Metro user interface. Such browsers will work as expected on the conventional desktop, but will only be accessible in the Metro environment when configured by users as the default browser.

As a Metro style enabled desktop browser, Firefox for Metro will be able to access Win32 APIs in addition to Metro's WinRT API stack. According to Bondy, Firefox for Metro will be built against the Windows Runtime C++ Template Library and will rely on XAML for the user interface.

They have already started by getting a trivial application to build and run in the Metro environment. According to Bondy, the general lack of developer resources and information about the obscure Metro browser application type has posed some challenges. Microsoft has published some relevant technical resources on MSDN, but these are said to be somewhat incomplete, which is unsurprising considering that Windows 8 is still under development.