It was almost a month ago that Mozilla announced it would be working on a Metro version of Firefox, however an important question remained. Would Metro Firefox be little more than a live tile that was more of a pain than it was worth? Or would Microsoft allow them to take over default access for opening links and other non-sandbox friendly operations? We finally have an answer, and even though it is still somewhat vague, it looks like Microsoft is going to great lengths to make sure users can replace Internet Explorer in metro should they feel so inclined.
According to Firefox developer Brian Bondy, in addition to classic desktop and Metro web browsers, Microsoft is going to allow a third category of app called “Metro style enabled desktop browsers”. Apps in this category would have a desktop version similar to what you are using today, and a metro style counterpart that would take care of operations done in a non-desktop environment natively. For example; if you click a link while in a Metro application, you get a Metro version of Firefox. If you click that same link in a desktop application, you get the desktop version.
By creating a third category of app Microsoft is also choosing to except web browsers from certain features such as Metro sandboxing, and unlock additional API’s such as background processing and extensions. These permissions are only unlocked in Metro mode however if you choose to make it the default browser, and the reasons for this are still somewhat unclear. Mozilla is planning to release the Metro and Desktop version of their Windows 8 browser in one package downloadable from the Windows Store, though they admit it remains to be seen if Microsoft will approve that approach since the policy at the moment is Metro only.
Microsoft spent years in court defending itself anti-trust allegations in regards to Internet Explorer, so it makes sense they might spend a bit of extra time making sure they play nice with competitors now so history doesn’t repeat itself.