Sony has aosp-roms with Android 4.4 for the Xperia L online. These firmwares, which are not intended for daily use, make it possible to have stock Android on an Xperia device to run.
The aosp-roms are available for Xperia Z, Xperia ZL, Xperia Tablet Z, Xperia S, but only the Xperia L is already on Android 4.4. The projects are hosted on Github. Users can after unlocking the bootloader and compile the files using adb in fastboot the firmware on their device flashing.
Sony warns that the firmwares are not suitable for daily use. So, for example, gps is not in all cases because the patches need to be performed. The firmware is based on Android 4.4, the latest version of Googles mobile operating system.
Sony wants to use the aosp-roms with the open-source community around Android support and in that way also own additions to aosp verify, so says the manufacturer. Sony is the only major manufacturer that does this on this approach, although some other manufacturers also firmwares without any skin and it available.
Update, 13:12: Originally was in this article that Sony for all devices on Android 4.4 based aosp rom online, but that is not correct: only the Xperia L has a 4.4-based firmware.
