International US QWERTY layout with AltGr dead keys via AutoHotkey script and MSKLC source.
In UltimateKEYS, all keys remain exactly organized as US QWERTY. Except, when AltGr or AltGr+Shift is pressed in combination with another key, other diacritics and symbols are accessible and some keys become dead keys.
In that way, it is - somehow - similar to the layout "United States-International" (on Windows), although this project moves all dead key combinations to the modifiers AltGr and AltGr+Shift. That way, this project solves the most typical issues, among which the quotes (' and ") can be used as usual (without pressing the spacebar afterwards), while the acute accent (´) and diaeresis (¨) are found on AltGr+' and AltGr+Shift+" respectively. This project has borrowed several aspects from the EurKEY Keyboard Layout (by Steffen Brüntjen).
This AutoHotkey script is a highly customizable version of UltimateKEYS. To work properly, the Windows keyboard has to be set to standard US QWERTY and at least AutoHotkey v1.1 (AutoHotkey_L) is required.