Change ctrl shift / from html comment to cfml comment

You can write an extension that defines a new language, maps the .cfml file extension to it, and defines "<!---" as the preferred block-comment style.  (The linked documentation refers to "Brackets," which is just the open-source flavor of Edge Code -- the instructions should work the same for both).  Because Brackets / Edge Code normally treats .cfml as plain HTML, you'll also have to write some code in your extension to remove .cfml from the list of HTML-language file extensions before you can add it to your new CFML language.  Overall, your extension would look something like this:

define(function (require, exports, module) {
    var LanguageManager = brackets.getModule("language/LanguageManager");
    LanguageManager.getLanguage("html").removeFileExtension("cfml");
    LanguageManager.defineLanguage("cfml", {
        name: "CFML",
        mode: ["htmlmixed", "text/x-brackets-html"],
        fileExtensions: ["cfml"],
        blockComment: ["<!---", "-->"]
    });
});

Hope that helps!

- Peter