Sony decided to prove that it is an important partner for the future of Mozilla Firefox OS, and released an experimental ROM for the Xperia E smartphone.
The Xperia Y smartphone is very simple, without major technical specifications. The description in Firefox and the mobile operating system already announced and what is the audience that Mozilla wants to catch.
Sony released this ROM for those who want to install it on their Xperia E, but not without several warning signs that to perform the bootloader unlock, the phone may void the warranty, and the procedure is done at your own risk.
If you own an Xperia E that was not released in Latin America and you want to take the opportunity to try Firefox OS, go to Sony's developer portal and follow the instructions to download and install the system. But if you are curious about the Mozilla system, but not to the point of having all this work, it is good that you investigate more especially in the videos that are about it on youtube.