Adding firefox did install firefox but gave following error while trying to execute on XO:
--------------------
$ firefox
Error: Platform version '13.0' is not compatible with
minVersion >= 12.0
maxVersion <= 12.0
---------------------
Here is my entry of configuration file
-------------------------
[root@fedora-arm examples]# tail -10 olpc-os-12.1.0-xo1.75.ini
[custom_packages]
add_packages=firefox
[adobe_flash]
plugin_path=/root/libflashplayer.so
[sugar_welcome_activity]
[buildnr_from_file]
path=latestbuild
--------------------------