So Firefox on Android is going to go native with its user interface:
The problem, however, is that interpreting and painting at the application level adds an unwanted overhead, which usually goes unnoticed on most modern desktop and laptop computers, but becomes a bottleneck in resource constrained devices like cell phones and tablets. Native widgets are handled by Android directly so it doesn’t require additional translation or memory to map how to draw them.
Faster startup, less memory consumption, and improved responsiveness are some of the expected benefits of such a move,which is not free of important new challenges, most notably: localization and add-ons support, both of which are completely XUL-oriented.
I like the Firefox browser on Android, but it crashes and randomly restarts so often, it is essentially unusable for me. Hopefully this planned change will actually make the browser useful.