When you start emacs from a shell, emacs inherits shell's environment variables. (true on Windows, Mac, Linux)
On Windows, when you start emacs from GUI, emacs also inherit environment variables, from the Registry.
On Mac OS X, when you start emacs from GUI, emacs does not inherit environment variables from your shell, but does inherit the system-wide environment variables from 〔~/.MacOSX/environment.plist〕.
On Mac OS X, you can start GUI emacs from shell, like this: nohup /Applications/Emacs.app/Contents/MacOS/Emacs &. This way, it'll inherit shell's environment variables.















