WChown
WGenode
WLightweight Portable Security
WLXC
WMicrosoft Baseline Security Analyzer
WOpenVZ
WOpenwall Project
WPaX
WPrivilege escalation
WPeter G. Neumann
WQubes OS
WReplicant (operating system)
WSecure by default
WSecurity-focused operating system
WSingularity (software)
WWhonix