Use only the left option key as meta key in Terminal.app

Solution 1:

If you aren't totally set on using Terminal, I believe that iTerm2 has a setting to just use one of the option keys as meta. If you are, is there a setting to maybe use the Esc key as meta? I know that it's more convenient to use the option key, but the Esc key might be easier to set.

Solution 2:

I have built a solution myself and it doesn't require abandoning Terminal.app in favour of iTerm 2.

It is a simple status bar app that runs in the background and rewrites all left Alt + $KEY key events to two key events in rapid succession, Esc, then $KEY; however, it only does this if Terminal.app is in focus.

You can find the source for the app here. You'll need Xcode to build it.