Most software I make, makes the CR optional (although some disallows it), and I do not usually use it in my own files, except DOS files; I still use CRLF in DOS

Most software I make, makes the CR optional (although some disallows it), and I do not usually use it in my own files, except DOS files; I still use CRLF in DOS files, as well as in existing files that already use CRLF for some reason. There may be some situations where it is helpful to have them separate, although for most uses (including most internet protocols) it isn't. But, I agree with the part about Windows that O_TEXT should not be used; you should use O_BINARY.