thumbledore

I only uploaded this so that it may serve as inspiration. It is still being tweaked.

Typing on a standard keyboard is not a great experience. Your thumbs idle while your weakest finger contorts to reach keys like escape and backspace. Exotic keyboards can remedy this, but lack portability.

thumbledore is a layout with 40±2 keys that is meant for keyboards with at least 2 or ideally 3 thumb keys per hand, but that also fits broadly within the constraints of a laptop keyboard.

• Each finger travels one key at most. Your thumbs pick up the slack.
• Graceful degradation. You can keep a somewhat consistent layout even when you're stuck on a laptop keyboard.
• Easy to remember. There is only one additional layer for symbols and one for navigation and function keys. That's it.
• One-handed control. The number pad can be controlled with just the right hand. Navigation keys can be controlled with just the left.
• Progressive learning. You don't need to learn everything all at once. I've found the symbol layer to be most important, so start with that.
• No regressions. Modifiers stack in a sensible way, and all common keys that you might want to press are still available --- for example, you can still emit a bare press of the right control key.
• No homerow mods. Overloading letter keys necessarily introduces time-based disambiguation, which can be fickle and introduces visual delay. You can use tricks to mitigate this and train yourself to work with it, but I have avoided them here.

Keys

Special keys are mostly controlled with your thumbs, whereas the keys for letters are symbols are controlled with the remaining symbols. These are the special keys:

1. ESC/fn. This key accesses the Function layer that contains the navigation keys and otherwise activates the Super modifier, useful for binding actions in your window manager. The key gets an additional function when you tap rather than hold it: it then triggers Escape, useful for modal applications.
2. RTN/fn. The logical counterpart to ESC/fn: tapping this one gets you Enter (Return). Ideally, you can still get repeating enters by double tapping and holding, but this isn't implemented everywhere.
3. The symbol key SYM accesses the Symbol layer for all the characters that would usually involve finger contortions. It is a sticky key: when you tap it, it will be activated for the following keypress.
4. The familiar shift key SFT is technically a modifier, but you could also see it as providing access to the Shift layer. It has also been turned into a sticky key.
5. The Control and Alt modifiers have been overloaded on the z/, and x. keys respectively. On a standard keyboard, they are still accessible as regular keys.
6. The compose key (or combo key) CMB allows you to type special characters by typing intuitive keys in succession. For example,
   CMB ' e becomes é.

Graceful degradation

On a Corne, with Colemak-DH as layout, thumbledore looks like this, with the home row highlighted in thick borders:

┌───┬───┬───┬───┬───┬───┐  ┌───┬───┬───┬───┬───┬───┐
│TAB│q !│w [│f +│p #│b ]│  │j ^│l 7│u 8│y 9│;:.│\|@│
├───╆━━━┿━━━┿━━━┿━━━╅───┤  ├───╆━━━┿━━━┿━━━┿━━━╅───┤
│BSP┃a *│r (│s -│t =┃g )│  │m ~┃n 4│e 5│i 6│o 0┃'"`│
├───╄━━━┿━━━┿━━━┿━━━╃───┤  ├───╄━━━┿━━━┿━━━┿━━━╃───┤
│sft│z &│x {│c $│d _│v }│  │k %│h 1│,<2│.>3│/? │sft│
└───┴───┴───┴───┴───┴───┘  └───┴───┴───┴───┴───┴───┘
            ┌┄┄┄┲┅┅┅┱┄┄┄┐  ┌┄┄┄┲┅┅┅┱┄┄┄┐
            ┊ESC┋SPC┋CMB┊  ┊SFT┋sym┋RTN┊
            └fn┄┺┅┅┅┹┄┄┄┘  └┄┄┄┺┅┅┅┹┄fn┘

However, on a standard keyboard without a split spacebar, you don't have access to so many thumb keys. To alleviate this, we move the right hand one key further along. For a tactile reminder, I recommend putting a sticker on your right index finger's home key. The remapping then looks like this:

┌────┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┐
│TAB │q !│w [│f +│p #│b ]┊   │j ^│l 7│u 8│y 9│;:.│\|@│   │
├────┴┲━━┷┯━━┷┯━━┷┯━━┷┱──┴┬──┴┬──┴┲━━┷┯━━┷┯━━┷┯━━┷┱──┴───┤
│BSP  ┃a *│r (│s -│t =┃g )┊   │m ~┃n 4│e 5│i 6│o 0┃  '"` │
├─────┺┯━━┷┯━━┷┯━━┷┯━━┹┬──┴┬──┴┬──┺┯━━┷┯━━┷┯━━┷┯━━┹──────┤
│shft  │z &│x {│c $│d _│v }┊   │k %│h 1│,<2│.>3│      /? │
├─────┬┴───┴┬┄┄┴┄┄┲┷┅┅┅┷┅┅┅┷┅┅┅┷┅┅┅┷┅┳┅┷┅┅┅╅┄┄┄┴┄┬───────┤
│ctl  │alt  ┊ ESC ┋       SPC        ┃ sym ┋ RTN ┊       │
└─────┴─────┴┄┄fn┄┺┅┅┅┅┅┅┅┅┅┅┅┅┅┅┅┅┅┅┻┅┅┅┅┅┹┄┄fn┄┴───────┘

Hopefully, this makes your right thumb rest on AltGr, rather than on the spacebar. Now, making an inward motion with your thumbs has the same result as on the ortholinear board. These (6×3 + 2) × 2 = 40 keys are the only ones you'll really need to access any key you'd find on a generic keyboard --- but you if you do have access to more thumb keys, like on a Corne, you can make your life easier with thumb access to Shift, Control, Alt or Compose.

Of course, on a laptop keyboard, Control and Alt are still also available in the bottom left.

Layers

The default layer doesn't change much from what you're used to (which may be QWERTY or something else --- I recommend Colemak-DH or Workman). The major difference is that capslock becomes backspace, avoiding the huge move your pinky would usually make.

◇ Symbol

The Sym layer has been crammed full with the remaining numbers and symbols.

Because the SYM key is pressed with your right-hand thumb, the left-hand side is preferred for the most common symbols (according to personal usage) --- except for number pad, which can now be controlled entirely with your right hand. There are two duplicate keys: / and ., which are also on the default layer but often needed in conjunction with numbers. For the same reason, you can get : by tapping . twice.

🮰 Function

The Fn layer contains a navigation cluster, placed so that you can control it with one hand. It contains directional keys, home/end, and pageup/pagedown.

The layer also has the function keys and provides access to the modifiers: tapping the keys labeled alt, ctrl and meta activates the corresponding modifiers for the remainder of the time that Fn is pressed.

This layer can be activated either via ESC/fn on the left or via RTN/fn on the right --- but it will only be activated for the keys pressed with the same hand! The keys on the other side will act as if they were pressed with the Super+Control modifier. This is convenient for quick access to window-manager shortcuts that you might want to set, such as navigating desktops and closing windows.

Pressing both Fn keys allows you to combine modifiers with the keys on the Fn layer itself, or to generate bare taps of said modifiers.

┌────┬────┬────┬────┬────┬────┐  ┌────┬────┬────┬────┬────┬────┐
│DEL │HOME│UP  │END │PGUP│PAUS│  │  F7│  F8│  F9│ F10│ F11│ F12│
├────╆━━━━┿━━━━┿━━━━┿━━━━╅────┤  ├────╆━━━━┿━━━━┿━━━━┿━━━━╅────┤
│BKSP┃LEFT│DOWN│RGHT│PGDN┃SCLK│  │  F1┃  F2│  F3│  F4│  F5┃  F6│
├────╄━━━━┿━━━━┿━━━━┿━━━━╃────┤  ├────╄━━━━┿━━━━┿━━━━┿━━━━╃────┤
│shft│MENU│alt │ctrl│meta│SYRQ│  │INSR│meta│ctrl│alt │CAPS│shft│
└────┴────┴────┴────┴────┴────┘  └────┴────┴────┴────┴────┴────┘

Usage

Install keyd (version >=2.3) and copy keyd/default.conf to /etc/keyd/.

Other

• Seniply has similar goals.