X11 is the X Window System; a graphical user interface used by some Unix applications and included in the operating system as part of Mac OS X 10.4. Allows Mac OS X to run Unix applications that are not designed to be used directly in the native Mac OS X execution and graphical interface layer. The X11 environment includes a server, a window manager, libraries, and necessary building blocks so that applications designed for X11 can work.
The previous update was published in order to solve the problems related to the stereo GLX representation used by some X11 applications for 3D visualization and that allows you to view these 3D images on 3D optical screens.
The minimum requirements are Mac OS X 10.4.8 or later and X11 1.1 or later.