The plan of Mobile Firefox was announced in October last year and the Mozilla community is now very busy to develop Mobile Firefox.
Fennec is the code name of Mobile Firefox, which is a desert fox. You may have seen a fennec in TV animation. The size of fennec is smaller than normal fox and it has big ears. So I think the name of Fennec seems to be suited well for Mobile Firefox.
The Mozilla Community opened the source code of Fennec and a guide of how to build it. It is a little bit intricate to build it because it is not merged into the Mozilla trunk.
After build and run, you can see the following appearance.
The basic features of browser were already implemented such as the navigation bar and bookmark menu. But, panning is a little bit slow and zooming is not working in the latest code.
Fennec can be built in Maemo Scratchbox and run on XULRunner so I'll post a way of how to build and run in N810 later. It would be helpful if you give any feedbacks to the Mozilla community after testing Fennec.