Due to the wide availability of Tcl/Tk, there is a good chance of getting Redet to work on most platforms. Platforms on which Redet is known to run are:
There are two implementations of Tk for Mac OS X: Tk-X11 and Tk-Aqua. Redet runs properly with Tk-X11 (for which, naturally, you must have X11 installed). It now also adapts itelf to Tk-Aqua, the native Mac OS X implementation of Tk. It is usable with Tk-Aqua but some details still require work. (Note that as of Mac OS X 10.4 "Tiger" X11 is an optional component provided on the installation CD.)
When changing locale, Redet obtains the list of available locales by executing the program locale, which may be available only on UNIX systems.