Starting with Generation 4, Xic and all other Whiteley Research products use the GTK-2 graphical user interface toolkit exclusively (see http://www.gtk.org for more information). The toolkit must be provided by the user's installation. This is almost certain to be the case under Linux, as GTK is a default part of virtually all Linux distributions. In FreeBSD, it will have to be installed from the ports or packages collection, if it wasn't automatically installed from the distribution DVD. For Windows, a complete GTK-2 installation package is available from Whiteley Research, which is a self-extracting .exe version of the zip distribution provided from www.gtk.org. One of these packages must now be installed on a Windows host. Similarly, GTK-2 must be installed on the Mac. This makes use of the X-window system, which also must be installed and running on the Mac. Although there is a version of GTK-2 that uses the native Quartz screen interface instead of X-windows, it has very serious flaws and is unusable at present.
The Win32 graphical interface previously used under Windows is now retired, as is the GTK-1 interface used in some earlier releases. Thus, all present releases will have precisely the same graphical interface, which will greatly simplify documentation, maintenance, and future development.
The GTK-2 toolkit handles the interface to the screen, window manager, keyboard, and mouse. It is not likely that there will be serious incompatibilities.