Tix, which stands for the Tk interface extension, adds an object-oriented framework for defining new widget types from existing widget types. Instances of these new widget types are called mega-widgets. Tix includes over 40 predefined megawidget classes and several commands for designing new ones. Figure 9-1 shows some examples of the mega-widgets added by Tix.

Tix also adds a few new standard widgets, commands for communicating with the Motif window manager, a form-based geometry manager, and two new image types: compound and pixmap.

Tix scripts are usually run using the supplied tixwish command interpreter. The command-line arguments for tixwish are the same as for Tk’s wish. Tix can also be dynamically loaded into a running Tcl interpreter using the command:

package require Tix

if the system is properly configured for dynamic loading.