Mozilla developers have announced that they have started work on a version of Firefox that would work in Metro interface of Windows 8.
This new edition of Firefox would be a metro style desktop browser which can work both as a desktop app and a metro app.
Mozilla developer Brian R. Bondy spoke about the initiative:
Firefox will fall into the third category, meaning you can run Firefox as a desktop application, and you can run it as a Metro application. Supporting the Metro side of things will require a lot of new code, so this is a very large project.
Unlike Metro applications, Metro style enabled desktop browsers have the ability to run outside of the Metro sandbox. Meaning not only can we build a browser, but we can build a powerful browser which gives an experience equal to that of a classic Desktop browser.
Metro style enabled desktop browsers have access to most Win32 API and the entire new WinRT API.
Unfortunately a browser can only participate in Metro mode if it is the default browser. So if Firefox is not the default browser on a system, you can’t use it in Metro mode. This is a decision made by Microsoft.
The Firefox Metro enabled desktop browser can be, and will be included and packaged in the traditional way. I’m not certain if it will be allowed on the Windows store or not since it is not of Metro application type.