I saw the Tengwar suggestions. If we’re going with a Tolkien language, I’d suggest Cirth, which as others have suggested is based on real runic languages.
My main preference is that they are simple and unique in nature. I think Japanese Kana are a good benchmark for complexity and aesthetics.
I ran across the Marchen alphabet and thought it would look really neat… and then I thought “Boy, some of these look a little… swastika-y.” So back to the drawing board!
Then I found Phags-pa. The characters are very uniformly sized, and I think they look mildly futuristic while not being overwhelming. I’m going to try to throw together a layout with them, but it may not turn out for me because it’s a top-to-bottom script, so the alignments go all over the place when I put them in the place of left-to-right characters. Fingers crossed.
@adam.ard +1 to Bamum. Google also makes a Bamum font, and I think the clean, geometric style of the Noto fonts would look good on a legend, so I recommend seeing what it looks like in that typeface.
The Visitor font and Atlantian are nice, but I’m strongly in favor of sticking with a dead language. Creators can be possessive, and I would rather not risk this layout becoming a distraction for J+K by prompting angry letters or threats.
Edit: Draft 1! Like a lemming, I forgot that lights are in the lower-left across the whole board. But this gives you an idea. Turns out Phags-pa just looks a lot like CJK characters when you use it like this.
Hm. The symbols are nice, but seeing this I think I’d quickly get annoyed at the full-on mirroring of the halves. Bamum, while not quite as regular in size, does have more symbols, and looks nicer to my eyes. Pity though that u+A6B2 (ꚲ) and u+A6B5 (ꚵ) look so much like Y.
Yes I agree, I’m not very fan of mirroring. I do prefer different halves, but made of the same font family for unity. Still vote for Bamum 
No, I also prefer full unique symbols. For some reason I think it would be useful (at some time) to have unicode points for each key, we might create keymappings with it or something like that.
@chrimifi’s last Phags-pa proposal really doesn’t look bad too (if it wouldn’t be mirrored), but I still prefer Mende Kikakui. I like the line thinkness (better than Bamum).
what about me? I am a poker :). I just want a cool lookin’ keyboard. You know a praying mantis pokin’ at a butterfly :D. Will runes be poker-compatible? Just jokin’…
P. M. poker
Wow, what a great thread!! Thanks a lot @algernon for taking my Mende idea and turning it into something truly beautiful! I’m also quite taken with @adam.ard’s work with Bamum - it’s quite hard to choose between them. In case it helps anyone else, here are the two full-size images for side-by-side comparison:
Both look stunning IMHO. I think I would prefer a thickness somewhere in the middle between the two, but it’s hard to tell without seeing how it would look with real keycaps illuminated by real LEDs. Also, I think I would prefer a bit more diversity than the Bamum layout has, but maybe a bit less than the Mende one.
But by the way this thread is going, I’m quite sure we’re going to end up with keyboards which look totally amazing!! Thanks again 
Agreed. I feel thickness and variety could use a compromise between the two. Hard to say though, since LED glow may distort that perceived thickness to some extent (in the dark anyway). Something to consider.
I was torn between Mende and Bamum, so ran both by my wife, and she leaned towards Mende. Her reasoning was that Bamum looks simpler, Mende is more… exotic? But my Mende proposal needs an update nevertheless, to make the fonts a bit thicker, and replace the duplicates.
One other thought. I think the butterflies on both of these look too modern and incongruent with the other symbols. I would prefer a more runic, minimalist symbol, but something still fairly clearly identifiable as a butterfly. I couldn’t find anything exactly like what I want via a google image search, but perhaps something somewhere in between the two butterflies on this page might work. I also like the runic aspect of the butterfly symbol on the bottom right of this page although I think it’s too plain compared to the symbols we already have.
A further possibility is to have the butterfly symbols drawn from a side-on view, like a slightly less ornate version of this one, and then have mirror images on both sides.
I realize I’m chiming in very late on this discussion, but I think the Inuktitut or Cree syllabics would serve the purpose beautifully, both visually and symbolically. Those writing systems were new inventions of the 19th century to fit polysynthetic languages that were not well served by trying to make the Latin alphabet work. A bit like the many departures from the old typewriter keyboards that the Model 01 embodies. Inventing a new tool for the job instead of sticking with the old familiar one regardless of how poor it is at accomplishing that task.
The problem I have with those two options is how limited they are in diversity of characters. Both syallbaries look like a small sub-set of characters that are then modified in different ways.
Both Mende Kikakui and Bamum were 19th century designed syllabaries as well, and Phags-pa has a similar history in making a script work for a language that it didn’t fit well.
I do prefer the Bamum symbols, they feel a bit more like letters to me, but the thickness needs to be tuned, as the png of the Mende looks cleaner to me than the Bamum one. Maybe that is due to using the JG Bamum Akauku Sans; it would be good to check with Noto Sans Bamum; putting those two side by side shows the Noto Sans Bamum to be much cleaner. (See the image below, JG Bamum Akauka left, Noto right).
Another thing we could look at is the Bamum supplement (U+16800 - U+16A3F) for inspiration for the palm keys; U+16811 might fit, U+16A21 when rotated, but I also like U+168D0 and U+169F7.
That’s one of the reasons I prefer Mende: it looks less like the symbols I’m used to, less letter like.
Noto definitely looks better, thanks a lot for the comparison image!
I like the right one there as-is, though I suppose it might be too complex.
Both the Bamum and Mende proposals look great, though I agree that a happy medium on line weight would be useful.
Yes, pretty sure it would be. Also, I think it would be nicer if it mostly matched the complexity of the symbols of the other keys - would be cool if they looked like “special” keys, but not completely incongruous.
Yes. That Noto font looks really promising!
I just downloaded the Noto, and will make the change in characters as suggested above, and change the font for all characters.
Thanks, excited to see this!!
See below. First is updated JG Bamum with new characters:
Second is Noto Bamum, also with the new characters.
I like the curvy-ness of the JG Bamum, but I like the thickness of the Noto Bamum better. Your thoughts?
