In the newest version of Nightly, you will need to open the menu and click on "Relaunch in Windows 8 Touch" to switch to Metro mode.

See: How do I launch Firefox for Windows 8 Touch?

Swarnava Sengupta said

In the newest version of Nightly, you will need to open the menu and click on "Relaunch in Windows 8 Touch" to switch to Metro mode. See: How do I launch Firefox for Windows 8 Touch?

I understand that, but I want to know how to enable that in the source code. I'm trying to make the browser have the Metro UI and the newest Nightly build doesn't have that feature.

The Metro development was stopped some 13 months ago.

https://blog.mozilla.org/futurereleases/2014/03/14/metro/

Swarnava Sengupta said

In the newest version of Nightly, you will need to open the menu and click on "Relaunch in Windows 8 Touch" to switch to Metro mode. See: How do I launch Firefox for Windows 8 Touch?

This is a old outdated article.

James said

The Metro development was stopped some 13 months ago. https://blog.mozilla.org/futurereleases/2014/03/14/metro/

I am aware of this; however, I want to enable it in the source code. I don't want just a desktop browser; I want a Metro UI one as well. That's why I want to enable the Metro UI in the source code. I'm building my own Firefox browser, if that clears anything up.

ubunturox104 said

James said

The Metro development was stopped some 13 months ago. https://blog.mozilla.org/futurereleases/2014/03/14/metro/

I am aware of this; however, I want to enable it in the source code. I don't want just a desktop browser; I want a Metro UI one as well. That's why I want to enable the Metro UI in the source code. I'm building my own Firefox browser, if that clears anything up.

Okay, scratch that. Is there a way that I can inject modern Firefox code into the Firefox 19 code?

Silly me, the answer was right here: https://wiki.mozilla.org/index.php?title=Firefox/Windows_8_Integration#Building_Locally

edit fixed link