Here are the files for two special keyboard layouts I have made up. The first of this is PhiKey (Philological Keyboard), which is meant to work like a normal US keyboard, but allow easy typing of special symbols, accents, and diacritics by holding down the right Alt key while pressing another key. The PDF explains the background, logic, installation, and use of this keyboard.
The second keyboard is a runic keyboard. I don't have documentation for it yet, but its installation will work much like that of PhilKey. It can in theory type all normal runes of the Older and Younger Futharks and the Aglo-Saxon rune rows, and should include most of the common graphic variants. It is probably not too much use without documentation, so I'll try and provide that before too long (don't hold your breath, though).