WAdium
WWindow Maker
WFreeDOS
WBSD Daemon
WBugzilla
WJava (software platform)
WEMule
WMediaGoblin
WPlan 9 from Bell Labs
WGNU
WWebGUI
WKDE
WKate (text editor)
WKDE
WKDE
WKrita
WAROS Research Operating System
WMozilla (mascot)
WOpenBSD
WMinix 3
WPidgin (software)
WTux (mascot)
WGIMP
WGIMP
WXfce