A few months ago there was a cheerful message from the boss of the Android Open Source Project Jean-Baptiste Queru. This informed at that time that the Sony Xperia S will be incorporated in the development of the AOSP. And since then there was also the first successes of the development of the AOSP team at Sony Xperia S.
The CyanogenMod is probably the best known and also the most popular Custom ROM are available for Android smartphones. Long did it take to appear after the release of Android 4.0 the first CyanogenMod versions, the conversion of Android 2.3 on Android 4.0 was a difficult step for the programmer.