Working in raw XML, though, is error-prone and tedious. To ease this process there is a freeware tool called Ukelele. Be sure to read the enclosed PDF for info on using the program.
To create an icon (with Devtools Icon Composer, for instance) for the Language Tool Bar, simply place a *.icns file with the same name as the Layout into the appropriate Keyboard Layouts folder. For example, German Numpad Point.keylayout and German Numpad Point.icns.
If anyone knows how to pack such a layout into a bundle or package, please tell how...

