The `html-mode' defined in the library `psgml-html' binds `tempo-complete-tag' to <M-iso-left-tab>, which I can't figure out how to type, even in X. It seems like it would make more sense to just bind it to M-TAB, since that's quite easy to type: it's just ESC TAB, regardless of how I run Emacs (terminal or X) or what WM/Desktop I use.