The Keyboard Layout for Europeans, Coders and Translators - Version for Mac OS X.
This is a port of the EurKEY Keyboard layout, which features a QWERTY baseline layout (=good access to braces etc.) with quick access to commonly used accented characters and Umlauts.
Status: The whole layout should be mapped now. Please report if you find any missing characters.
Copy the two files EurKEY.keylayout and EurKEY.icns to your library, either system-wide (/Library/Keyboard Layouts) or for your local user (~/Library/Keyboard Layouts). A system-wide installation is preferred to ensure the layout is available to all applications. (See also this Superuser answer.) For the changes to take effect a restart is required.
After the restart go to System Settings > Keyboard > Edit > + and search for EurKEY v1.2. After adding the layout select its symbol from the menu bar icon.
The Layout itself is licensed under GPLv3. The EU flag icon is taken from Iconspedia, created by Alpak and licensed under CC