Similar to XDarwin

WxWidgets

X Toolkit Intrinsics

XDM (display manager)

X.Org Foundation

X.Org Server

Template:Desktop environments and window managers for X11 and Wayland

X11 color names

XBill

X BitMap

XCB

Xeyes

Xfce

Xfig

XFree86

Xgl

Xinerama

Xlib

Xming

XMule

Xpdf

X PixMap

XQuartz

RandR

X Rendering Extension

Xsun

Xterm