WAliOS
WAOKP
WAsteroidOS
WBada
WBlackBerry 10
WCopperheadOS
WEMUI
WFire OS
WGEOS (16-bit operating system)
WHiOS
WHome screen
WIOS
WIOS 13
WIOS 14
WIPadOS
WIPadOS 13
WIPadOS 14
WIPhone OS 1
WIPhone OS 2
WLinaro
WLuneOS
WMaemo
WMagic Cap
WMeeGo
WMer (software distribution)
WNokia Asha platform
WNokia X platform
WOne UI
WOpenmoko Linux
WOptimus UI
WPalm OS
WParanoid Android (software)
WPureOS
WQNX
WReplicant (operating system)
WSailfish OS
WSamsung Experience
WSeries 30
WSeries 30+
WSHR (operating system)
WSymbian Foundation
WSymbian
WTizen
WTouchWiz
WUbuntu Touch
WWebOS
WWindows 10 Mobile
WWindows Mobile
WWindows Phone
WWindows Phone 8.1