Okay, here's what I've done for the upcoming release. (It is a kind-of patch on the existing setup, but perhaps that's appropriate, since the right long-term solution is to move everything to #lang.)
When a file is opened, and the language that would have been used is a language that returns non-#f from get-reader-sexp (that means that that language is one that adds metadata to the save file; currently this includes the deinprogramm languages and the HtDP languages (and possibly others)), then the language used is instead the not-a-language language (that is the one you get when you have a fresh preferences file). In other words, I believe that this will have this effect: - after choosing a teaching language from the language dialog - and then opening a file that does not contain a prefix (no #lang prefix and no teaching languages prefix) - the language for that window will be set to the not-a-language language. And hopefully no other effects. Testing welcome! Robby _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/dev