In Eclipse Emacs mode, is there any way to remap or add the Alt key to the Esc key?

I'm used to the Emacs use of Esc for Metakey. In eclipse may I change the Esc key to开发者_开发知识库 be the Alt key?

Nope, I don't think there's a way to do that. The relevant Eclipse UI docs state:

The recognized modifiers keys are M1, M2, M3, M4, ALT, COMMAND, CTRL, and SHIFT.

ESC is only a "normal" key. Emacs handles ESC specifically, so that it acts like kind of a modifier.

On windows plateform you can use AutoHotkey to remap Esc to Alt

Just add this to your Autohotkey script :

#IfWinActive ahk_class SWT_Window0
$Esc::Alt
#IfWinActive

you may need to adjust the first line to match the class of your Eclipse window (use the windows spy tool provided in Autohokey).