I try to live by the rule that whenever I realize that I'm well into Tinkerland I should backtrack one step. That makes sense to me – better not to change something than to tweak it and most likely gain nothing? Even if the psyche sometimes has a hard time accepting that argument.

My experiences also have time and again proven this principle sound. I have been dabbling and tinkering with my keyboard setup for the better part of the last decade, and in my own view have ended up with a mix of conservation and optimisation that suits me very well indeed. I usually end up with precisely that one step back from where my uncurbed enthusiasm took me!

The key to successful further tinkering for me has been to add layers! When the AltGr mappings were played out and kept to a few concepts (dead keys, and symbols/glyphs that may be necessary in general latin script and aren't on dead keys), an Extend key/layer for navigation and editing and multimedia keys. Next (not well implemented unfortunately) another Extend layer for NumPad++. Etcetera.

You need two things: To set the Extend layer option, and a Level5 switch. I've separated these, so you could use something else than Caps as your Extend key as long as you can set it as a Level5 shift key. (Your choices without editing XKB are lwin, rwin, ralt and lsgt – and I've added caps.)

Are you on Ubuntu? In the Keyboard Settings GUI there's an Options button with different categories. One lets you set a Level5 key (I've added Caps as an option there) and the mappings themselves are chosen from the "Miscellaneous Compatibility" features (because something vaguely similar was put there already).

If you're using setxkbmap or the config file directly, it's the 'misc:extend' and 'lv5:caps_switch_lock' (or one of the other keys) options:

setxkbmap -option lv5:caps_switch_lock,misc:extend

Glad it worked. I see that I did write this in the original post – but there's a lot there by now so I wouldn't expect anyone to find everything. :)

It should work with every layout – that doesn't use levels 5-8. To my knowledge, only a few ones do including a fairly experimental Canadian/International one. Other options like mouse pad overlays may use the levels too in which case there'll be a conflict, but in general this method is underused and safe to touch. Unfortunately, I still can't make the A/S/T modifiers work. :(

Can you tell me how to map the lvl5 of the A, S and T keys to Alt, Shift and Ctrl respectively with Xmodmap, then? It should work so that <lvl5_switch>+S+T+<arrowleft> for instance indeed selects the previous word as expected.

XKB has 8 shift levels but few layouts use the ones beyond 4; the Canadian International is a notable exception.

Nice rule of thumb. But I'm still not sure you can do what I need with Xmodmap at all...

I apologize for my previous behaviour. It was thoughtless.

Edit: I got it working with setxkbmap.

Also, is the modifier for level 7 called ISO_Level7_Shift? If not, then what is it?

Also, when you tried out xmodmap did you find out if level2 (3rd and 4th characters defined, used with mode_switch) replaced any of your layers? I was thinking that maybe you could actually use both xkb and xmodmap without having to just use xmodmap. If you don't define level 3 (5th and 6th characters defined), then it shouldn't affect your altgr layer. I'm pretty sure that I have used the altgr level defined in the colemak xkb for keys that I have mapped with xmodmap by touching the altgr portion. I'll reboot and test this when I get a chance (currently I have overwritten the altgr layer with a tab layer), but I'm mostly sure that this should be feasible.

I guess that the advantages would be the use of alt and shift on the caps layer.. you could also use caps+ s (shift in the layer) to get a new layer (4th key defined in xmodmap) if you wanted. Media keys would still work I think. I'm not sure about mouse movement though (is that possible in xkb?). I'm trying to weigh the pros and cons of an extend layer in xkb v in xmodmap.

The other cool thing would be that if the mode_switch layers don't affect any xkb layers, you would have 2 extra layers. If they do affect some level from 5-8 xkb, then it could just serve as a replacement.

@Javix: If the function keys are giving you trouble (I think mine work fine?!), find the X11/xkb/symbols/extend file and comment out all entries for <FK##>. The Extend mappings for function keys are multimedia functions, that usually don't work out of the box for Debian/Ubuntu anyway. If you try to remap manually using the GUI settings on Ubuntu you'll even run into a bug that maps to Lvl5_switch (the Caps key) instead of the resultant key.

Note that the number keys with Extend turn into function keys, for easy access. Doesn't work quite as well as on windows/pkl where Caps+A+4 produces Alt-F4, since the A/S/T modifiers aren't working under xkb (yet).

@angelic_sedition: Hey, no problem.

- I haven't touched lvl9 at all. It's supposed to be there even under Windows, but not implemented anywhere I know of. Lvl7 however is just lvl5+lvl3, i.e., the combination of lvl5 and AltGr (usually)! It has no separate switch although you could make one.

- When I tried XModmap it wiped my AltGr layer even with those levels unmapped. I too thought of using both (XModmap only for A/S/T) but I haven't gotten further with it. And yes, it'd be fun if those extra layers turned out to be available – but I fear that XModmap will not be with us forever so I try not to base myself too heavily on it.

Update: Ghen's Rulemak for Cyrillic script has been added as 'Russian (Colemak, phonetic Rulemak)'. Yay!

I've been trying several things for the Extend mapping modifiers (actions, replace key, Overlay1...), but they still aren't working. Frustrating, to say the least.

I'm not sure what you mean by a separate package, as I have no experience making those. Sounds nice – do you know how to do it?

In order to work though, I think it has to modify at least some system files? Well, now that I think about it the only real reason to modify the system files is to see my changes in the option menus (which is all done in the rules component). It might be a lot better to make additional files alongside the originals, and just patch the rules components if you want the menus to show my stuff. Good thinking! :)

On a side note, it seems that my Colemak[eD] has re-entered a more dynamic phase of development! I've managed to get the Extend layer to work much better for Linux after two years of failed attempts (yay!), and I've decided to split out the files so that as few system files as possible have to be patched, like you suggested.

Also, I've come to the conclusion that the Greek letters αβγδε aren't used much so they should give way at least to ÷ו that I actually use quite often – especially the bullet. It's more of a toss-up for µ and π. I originally put almost all the Greek on unshifted AltGr positions for consistency but I guess that's a minor boon and it's broken by αδ being on the same key anyway. In sum, I'll keep π on unshifted AltGr and move βγεµ to shifted positions unless someone has a convincing argument to the opposite effect. (No? Didn't think so. Who cares, right?) ;)

I have no idea how to make packages for Ubuntu, but for Arch Linux it is super easy. However, what I failed to communicate clearly in my previous post was that I was hoping that you could provide your layouts as a set of files seperate from the ones provided by xkb. This way Colemak[eD] can be installed alongside the files already present in /usr/share/X11/xkb. From your edit it seems that this is what you're going to do going forward, which is great!

Now for something relating directly to the layout. There is this silly Menu key, positioned between AltGr and the right Control key. Normally this key functions as a right mouse button click, which I find rather useless. Moreover, with a non-wide layout, this key is pretty hard to reach. However, now that my fingers are shifted one key to the right, the Menu key is in the position where AltGr used to be. (I began noting this when I transitioned to the wide layout; I kept hitting the Menu key instead of AltGr :p)

This key could be put to better use. I propose to turn it into a modifier key akin to AltGr, and put common accented characters there. For instance, for Portuguese it would be very nice to not have to use dead keys to input letters such as ã, ê, í and so on.

WONDERFUL NEWS MY FRIENDS! WOO HOO!

I just made the Extend modifiers (A/S/T) work as they should with XKB so they're as useful as they are under Windows/PKL. That's *great* news to me I have to say! I've been working on this problem on and off for two full years, and it's been a lot of head scratching and failed attempts I can tell you.

As you can see, I'm quite stoked. This is an integral part of the goodness of the Extend mappings. There are a few quirks left: Most notably the Undo key still doesn't work, sadly. If you press Caps+S+N (for Shift+Left) you'll select the previous character as expected, and Caps+T+N (Ctrl+Left) jumps back a word as expected – but Caps+S+T+N doesn't register the Left press as I think that's too many keys for the X server! What works though is to press Caps+S+T, let go of the S only and then hit the arrow keys to start move-selecting around.

For the technically inclined: What finally worked for me was to use SetMods() actions for the modifier keys themselves, and RedirectKey() actions for the arrows and other keys that need to be modified by them. As I found out early on, mapping to the key symbolic names alone did nada. Intuitive, huh? ;) I got in contact with Sergej Udaltsov himself, the maintainer of xkb-data. Talking with him about the Extend problems enabled me to see the solution. Thanks, Сергей!

Just in: WTFLOL – I managed to get the Undo key (and Redo on Caps+S+Z) to work as well as Alt-F4! Man, I'm on a roll.
But I have to tell you, that was the ugliest line of code I've seen in xkb so far.
Shortly after, the F keys and wheel scrolling were also brought to heel. Wow.

Well Alfonz, thanks for chiming in! Looking at the topic post I realize that it's confusing and arcane. Linux often is, unfortunately. I want to improve on that, and thank you for your feedback.

One problem is that there are many Linux distros and several graphical environments to choose from. When I said "Ubuntu" I made a mistake because I meant "default Ubuntu" – which again has moved from the Gnome environment to its own Unity environment. Already, confusion reigns.

Also, the Big Bag topic is so ... well ... big, that you probably can't read it all without getting a headache. Not sure what to do about that, except to try and make it clearer in places.

If I remember correctly, in XUbuntu there was still the Options... panel under keyboard settings that you could use to set the Misc:Extend and Level5:Caps_switch_lock options needed for a working Extend layer. Furthermore, in XFCE I think you can still set your keyboard model in the GUI (to use Angle and/or Wide mods)? In Gnome you can't do that anymore and have to edit the files and/or use the setxkbmap command.

I recommend just editing the /etc/default/keyboard file, that's what I do most of the time. If you want to see something happen right away, there's the setxkbmap command. These are described at the end of the topic post.

I have added some clarifications to the main topic. Hope we can make this understandable! :)