I edited ~/.Xmodmap to set keycode 118 to Control_L, so that I have the same functionality for CTRL on both sides of Space. I had to remove and add Control_L to control and it works fine now.keycode 127 = Insertremove control = Control_Lkeycode 118 = Control_Ladd control = Control_Lkeycode 135 = ISO_Level3_Shiftkeycode 108 = spaceremove mod1 = Alt_Lkeycode 94 = Alt_L ISO_Next_Group Alt_L ISO_Next_Groupadd mod1 = Alt_LNow Alt+Tab doesn't work, even though both Alts work the same way otherwise. Alt+Tab with the new Alt switches to 1 other program and then back to the first one. It doesn't show the task switcher menu at all.Output of xmodmap -pm:[hax@localhost ~]$ xmodmap -pmxmodmap:  up to 4 keys per modifier, (keycodes in parentheses):shift       Shift_L (0x32),  Shift_R (0x3e)lock        Caps_Lock (0x42)control     Control_L (0x25),  Control_R (0x69),  Control_L (0x76)mod1        Alt_L (0x40),  Alt_L (0x5e),  Alt_L (0xcc),  Meta_L (0xcd)mod2        Num_Lock (0x4d)mod3      mod4        Super_L (0x85),  Super_R (0x86),  Super_L (0xce),  Hyper_L (0xcf)mod5        ISO_Level3_Shift (0x5c),  space (0x6c),  ISO_Level3_Shift (0x87),  Mode_switch (0xcb)Output of xbindkeys -k for the old Alt:[hax@localhost ~]$ xbindkeys -kPress combination of keys or/and click under the window.You can use one of the two lines after NoCommandin $HOME/.xbindkeysrc to bind a key.NoCommand    m:0x8 + c:64    Alt + Alt_LOutput of xbindkeys -k for the new Alt:[hax@localhost ~]$ xbindkeys -kPress combination of keys or/and click under the window.You can use one of the two lines after NoCommandin $HOME/.xbindkeysrc to bind a key.NoCommand    m:0x8 + c:94    Alt + Alt_LOutput of xev for the old Alt:KeyPress event, serial 37, synthetic NO, window 0x3e00001,    root 0x9b, subw 0x0, time 10657877, (328,658), root:(1612,798),    state 0x0, keycode 64 (keysym 0xffe9, Alt_L), same_screen YES,    XLookupString gives 0 bytes:     XmbLookupString gives 0 bytes:     XFilterEvent returns: FalseKeyRelease event, serial 40, synthetic NO, window 0x3e00001,    root 0x9b, subw 0x0, time 10657981, (328,658), root:(1612,798),    state 0x8, keycode 64 (keysym 0xffe9, Alt_L), same_screen YES,    XLookupString gives 0 bytes:     XFilterEvent returns: FalseOutput of xev for the new Alt:KeyPress event, serial 40, synthetic NO, window 0x3e00001,    root 0x9b, subw 0x0, time 10659997, (328,658), root:(1612,798),    state 0x0, keycode 94 (keysym 0xffe9, Alt_L), same_screen YES,    XKeysymToKeycode returns keycode: 64    XLookupString gives 0 bytes:     XmbLookupString gives 0 bytes:     XFilterEvent returns: FalseKeyRelease event, serial 40, synthetic NO, window 0x3e00001,    root 0x9b, subw 0x0, time 10660077, (328,658), root:(1612,798),    state 0x8, keycode 94 (keysym 0xffe9, Alt_L), same_screen YES,    XKeysymToKeycode returns keycode: 64    XLookupString gives 0 bytes:     XFilterEvent returns: False
xmodmap Alt+Tab doesn't work with new Alt_L key
x11;keyboard layout;xmodmap