TR - Many applications need to remember things about themselves, like GUI appearance, default values, last opened files and so on. Since Tcl is cross-platform, once a program is deployed on different platform, you want to handle this point in different ways. There are several places, where you can or should store data. A short and simple procedure is described in: Application-specific RC files.
Unix
User specific settings often go in the home directory in a dotted file like ...
file join $env(HOME) .configFile
GUI appearance is normally configured via the option database
Windows
... work in progress ...