Open file with. For convenience while testing your exported files on your Macintosh, select which application should open when you double — click one of these HTML files. This sets the Mac 'Creator' data to associate the file with the chosen application.
The list of possible editors offered in the pop-up list is read from the file "html_helpers.xml" [sic] in the Tinderbox application package; you can edit this file to add your favourite editor if not listed (back-up the original file first and take care to follow the existing file syntax). Default = 'TextEdit'.