

The source code for X11 is available from Apple.

In Mac OS X Leopard, X11 was updated to use X.Org Server (X11R7.2) rather than XFree86. "Rootless" means that X window applications show up on the Quartz desktop, appearing like any other windowed Quartz application (that is, not in a virtual desktop contained within another window). This implementation includes an XFree86 4.4 based X11 window server, Quartz rootless window manager, libraries, and basic utilities such as xterm. In Mac OS X 10.4 Tiger, Apple's X11 implemented X11 protocol release 6.6 (X11R6.6). Mac OS X 10.5 Leopard, Mac OS X 10.6 Snow Leopard, and Mac OS X 10.7 Lion installed X11.app by default, but from OS X 10.8 Mountain Lion on Apple dropped dedicated support for X11.app, with users being directed to the open source XQuartz project (to which Apple contributes) instead. In Mac OS X 10.4 Tiger X11.app was an optional install included on the install DVD.
Xming for mac for mac os x#
X11.app was initially available as a downloadable public beta for Mac OS X 10.2 Jaguar and later included as a standard package for Mac OS X 10.3 Panther.
