Sony releases Firefox OS experimental ROM for Xperia E
Here is the official demo of the Firefox OS running on the Xperia E
Since this is an experimental version, the OS might be unstable, and the radios don’t work yet.
The Firefox OS experimental ROM is available for unlocked Xperia E devices, and you also need to unlock the bootloader for these phones manually. You can download and read the complete set of instructions to flash the Firefox OS on Xperia E from the source link below.