This is a keyboard for Windows with X compose key-style AltGr combinations built in. Painstakingly created because I had to use Windows for a while and couldn't live without shortcuts for ellipses and em dashes.
This page lists common key combinations, most of which work with this layout.
To edit this keyboard layout yourself, you'll need Microsoft Keyboard Layout Creator 1.4 and .NET Framework 2.0.
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.