Jolla first announced that it was looking to bring the Sailfish OS to an Xperia device earlier in the year. Fast forward to today, and Jolla has announced that Sailfish X for the Xperia X is now available for purchase and download.
This secure operating system has Android app support and is supported on the single SIM version of the Xperia X only. Once you purchase the ROM, you will be prompted to download and install Sailfish X straight away. If you want to give the ROM a try then head over to the link here.