xmodmap

! `xev` and `showkey` to see which keycode is pressed
!old keys
!xmodmap -pke |grep Something

!Double Shift makes Caps_Lock
keycode  50 = Shift_L Caps_Lock Shift_L Caps_Lock
keycode  62 = Shift_R Caps_Lock Shift_R Caps_Lock

! former Tab
keycode  23 = BackSpace

! former BackSpace
keycode  22 = Delete

! former Control_L
keycode  37 = Super_L

! former Super_L
keycode 133 = Alt_L

! former Alt_L
keycode  64 = Control_L

! former Alt_R
keycode 108 = Control_R

! former 
keycode 105 = Menu

! former Ctrl_R
keycode 134 = Alt_R

!! CapsLock is now AltGr aka Multi_key
keycode  66 = ISO_Level3_Shift Multi_key ISO_Level3_Shift Multi_key

! Before assignment the modifier keys need to be empty
clear lock
clear control
clear mod1
clear mod4
clear mod5
add Control = Control_L Control_R
add mod1 = Alt_L Alt_R
add mod4 = Super_L Super_R

! Shift + space used to equal middle dot ·
keycode 65 = space U00B7 space U00B7

! AltGr + s = Tab
keycode  47 = s S s S Tab

! AltGr + Qwerty's I/K/J/L (Dvorak's C/T/H/N) => Up/Left/Down/Right
! can't make Shift+Up/Down => PageUp/PageDown. Why? Y.Y
keycode  31 = c C c C Up Prior
keycode  45 = t T t T Down Next
keycode  44 = h H h H Left
keycode  46 = n N n N Right

! AltGr + Qwerty's U/O (Dvorak's G/R) => PageUp/PageDown (aka Prior/Next)
! I have no idea why these two lines don't work
!keycode  30 = g G g G Prior
!keycode  29 = f F f F Prior

! AltGr + Qwerty's Q/A => PageUp/PageDown aka Prior/Next
keycode  24 = semicolon colon semicolon colon Prior
keycode  38 = a A a A Next

this is how it looks

https://twitter.com/myguidingstar/status/727800330872717314