An U.S. keyboard layout with Estonian keys and the Euro-sign for Mac OS X. I really dislike swapping keyboard layouts all the time and using the Estonian layout for programming is no good.

This is a "port" of the immensely useful "US keyboard with Estonian letters" Linux keyboard layout.

mkdir -p ~/Library/Keyboard\ Layouts; \
  curl -Sso ~/Library/Keyboard\ Layouts/us_ee.keylayout \
  https://raw.githubusercontent.com/madisp/us-ee-keylayout-osx/master/us_ee.keylayout

Created with the wonderful Ukelele OS X keyboard layout editor.