Tk has the ability to embed a toplevel inside another, or inside a frame. The -use and -container options are used for this, along with [[winfo id]]. For example: toplevel .top -container true toplevel .embed -use [winfo id .top] or: frame .f -container true toplevel .embed -use [winfo id .f] This can also work across processes on UNIX (and possibly Windows). The [wish] application also takes a -use option which works in the same way (the root "." window becomes embedded). On [MacOS X], however, this embedding is only supported within a single process (so, for instance the -use option to wish will not work). [Jim Ingham] writes on the tcl-mac mailing list: ''"So I talked with some folks who work on the MacOS X WindowServer, and they said that there is currently no way to get a window ID that will work across processes. So -use will only work in one process on OS X."'' [NEM]. ---- [[ Category ?? ]]