The tab key in BBEdit inserts a literal tab character, or advances to a tab stop. It doesn't indent the line, which is what I would argue it should do when writing code.
> When this option is on, you can press the Tab key to invoke the Shift Right command, or Shift-Tab to invoke the Shift Left command; this may be useful for those accustomed to Windows editing key behavior. When this option is off, pressing Tab will insert a tab character in the normal manner. This option is off by default.
I think this is already identical to tab behaviour in Emacs, just not by default.
