nbecker(a)fred.net writes: I agree that this would be an excellent feature. I see 3 (well 4) ways of implementing such a thing: 1) Save the current buffer to some temp file, then use the ordinary diff tools. 2) Even though I don't see it in "man diff", it looks like diff will treat a file arg of "-" as meaning standard input. One could devise a way to get XEmacs to feed the contents of the current buffer to a diff subprocess. 3) Load the file into another window and use the "compare-windows" function. 4) Wait until one of the wizards on the list says, "You dummy, just type M-C-*&^ with a prefix arg..." ;-)