I like the design goals of Colemak, but found that it does not work that good for non-english languages:

https://forum.colemak.com/topic/2328-an … languages/

When one writes significant amounts in non-english languages an improved layout which is more robust to be used with different languages is needed IMO. [1]
I tried to come up with a layout which follows the same design goals as Colemak, but achieves that improvement. My suggested layout was developed totally independent from Colemak, but in the end it looks relatively close to Colemak. That is to be expected, because I followed the same restrictions (not too many key changes, very few hand changes, keep zxcv shortcuts...)

I came up with a layout which has roughly the same performance results in layout analyzers like Colemak for English, but is vastly improved for other languages. In addition the "DH-problem" that part of the people experience in vanilla Colemak to have to stretch the index finger to the center , is avoided as well.

The basic character layout looks like that:

1  2  3  4  5  6  7  8  9  0  -  =
y  w  d  f  ;  q  l  o  u  p  [  ]
a  r  t  s  g  j  n  e  i  h  '
z  x  c  v  b  /  m  ,  .  k

On an non-english keyboard the non-char keys or special char keys could be kept like in the native layout. For example in German the layout would then look like follows and keep most umlauts and special chars in their original locations:

1  2  3  4  5  6  7  8  9  0  ß ´
y  w  d  f  ö  q  l  o  u  p  ü  +
a  r  t  s  g  j  n  e  i  h  ä
z  x  c  v  b  -  m  ,  .  k

I think the following analyzer results indicate that the layout does achieve my design goals and is a serious improvement over Colemak-(DH) for German, Finnish, French, Spanish,  and Dutch (I manually checked that there are not ugly bigrams for Dutch), while largely keeping the good English performance! [2]

The following table lists the traditional keyboard and fingering. Other keyboards (ergonomic, Matrix) have slightly different numbers, but typically do not change that much.

Language  sf-bigrams     score     left/right
English      1.85%        1.8        45 55
English      1.7%         1.8        45 55      - alternative fingering
Finnish      2.25%        1.8        40 60
German       2.4%         1.7        46 54
French       2.6%         1.7        44 56
Spanish      2.7%         1.8        46 54
Danish       2.8%         1.8        47 53
Swedish      2.8%         1.8        50 50
Polish       4.2%         2.2        50 50

and in comparison Colemak

Language  sf-bigrams     score     left/right
English      1.7%         1.8        45 55
German       5.0%         1.8        47 53
Finnish      3.7%         1.7        40 60
French       3.6%         1.7        48 52
Spanish      3.2%         1.8        49 51
Danish       4.3%         1.8        48 52
Swedish      4.1%         1.8        52 48
Polish       3.8%         2.0        49 51

For most tested non-english languages my layout suggestion is better than Colemak. Only for Polish Coleman "wins".

My suggested layout is pretty robust in that sense that one can move some letters around (with some thought and possibly double-checking in the analyzers) and optimize for personal  preferences or the most used local language(s). Possibly the layout could be optimized to perform better for Polish, but still keep the good English performance (mostly). For example moving the z. That will likely be at the cost of other languages of course, but could be interesting for Polish people. :-)

In general possible layout variations are changing the left hand home-row order from 'arts' to 'astr' or 'arts' (the latter only for non-German languages, because otherwise one would get an not so nice SFB with sc). Although in the current layout 'arts' performs best overall.

Another possible variation is to move b, q, y, ; (ö-key for Germans). Here y should be kept on the left side, to keep bigrams low.

j could be moved for non-Dutch languages (for Dutch it is critical to keep it in the middle row when k is on the bottom row!). p could also be moved (ph is a bigram, but not that often that it does hurt that much) possibly, but overall I found that it is best to keep it in place.

In general I decided to keep a letter in the qwerty position when a change did gain only very little or seems to make the layout less robust.

Critical for the performance is the right hand side with 'lou' on the top row above 'nei'. This must not be changed and is a significant difference to the Colemak layout. I think that's the heart of my layout suggestion, which makes it suitable for several latin-char languages.

I have tried earlier versions of the layout a bit for some days and optimized it till I reached this state. I think it will be very hard to improve on that layout when one does not want to degrade the performance overall. If you can come up with global improvements I surely would like to hear those!

For a combination of two specific languages (especially others than German-English) a (slightly) modified layout can likely perform a bit better. See the example above for Polish especially, but maybe also for the northern languages -- which I do not speak / need.

When someone wants to try that layout I think it really might be worth it. Especially if you write English plus any combination of French, Spanish, German, Finnish or Dutch. I personally now started to learn that layout. Btw, this is the first layout change in my life. I come from 80 wpm with qwerty and hope to achieve the same or higher speed in the not too far future! :-)   But first days practice are not easy for sure!

Possibly I will give a name to the layout. Maybe something like MultiMax as nod to the ..maks layouts, but also pointing in the direction that it's optimized for multiple languages and tries to achieve a close to maximum benefit with not too high efforts :-)

In addition I think that Colemaks multi-language input via the AltGr key is not a viable solution for everyday typing non-english languages (when touch typing blind -- I do not care about hunt and peek typing concepts). Especially because the AltGr-key can not be reached reliable with the thumb or pinky on many keyboards. It is a key which often moves in relation to the hand position for example between desktop and laptop keyboards. I think a layout must be robust in the sense that it can be used on ANSI and ISO keyboards and also work fine with the often somewhat altered laptop key positions.

I tried to get the most used characters for the European languages on the strong fingers. I consider the middle finger especially strong (also in the upper row and bottom I think it is a fairly easy key to press)

When I was looking for a good layout I had a look at the common bigrams and did not only look at the same-finger-bigram (SFB) numbers, but took a closer look to try to avoid the really ugly SFB's, like needing to jump with from top to bottom like (qwerty tv or qwerty qz). I think bigrams on strong fingers like qwerty de, ki, lo are not that much of a real problem for example.