MIUI - Xiaomi MIUI Official Global Site. MIUI is a customized Android ROM developed by Xiaomi for smartphones and tablets. MIUI Forum offers ROM downloads for 251 devices including Mi 6, Mi MIX 2, Redmi Note 4 and others.
Pixel Experience - PixelExperience is an AOSP based ROM, with Google apps included and all Pixel goodies (launcher, wallpapers, icons, fonts, bootanimation).
Android - Android is an open source mobile operating system initially released by Google in 2008 and has since become of the most widely used operating systems on any platform.
Evolution X - #KeepEvolving!
LineageOS - Operating system for smartphones and tablet computers, based on the Android
crDroid - crDroid is designed to improve the performance, reliability and customizability of stock Android.