Purpose: to discuss this great looking interface, provide tips on using the toolkit, and hopefully deal objectively with the current Tix versions.
Ioi Lam originally created Tix. His major technical concern appears to be enhancement of Tix's functionality. His code is at http://tixlibrary.sf.net/ .
Mike Clarkson maintains the stable release at http://tix.sourceforge.net . The main focus is stability and portability to other interpreters like Python.
Python includes support for Tix along with Tkinter as part of recent releases (since 2.1), but you will need the version from http://tix.sourceforge.net .
It is documented in the stardard Python Library Reference: http://www.python.org/doc/current/lib/module-Tix.html
This makes possible such projects as the Tixapps framework http://tix.sourceforge.net/Tixapps/ which is a library and suite of programs, including Tixinspect and TixDebug, which work as either Tcl or Tkinter applications.
Perl/Tk builds incorporates most of Tix; notice, for example, [L1 ].