Every "split" mechanical keyboard currently being sold that I know of

split_keyboards.md

• Kinesis Freestyle (Terrible key switches. Mushy and un-lovable)

• Kinesis Freestyle Edge (Traditional layout with too many keys, mech switches, proably too big to be tented easily/properly)

• Matias Ergo Pro (Looks pretty great. Have not tried.)

• ErgoDox Kit (Currently, my everyday keyboard. Can buy pre-assembled on eBay.)

• ErgoDox EZ (Prolly the best option for most people.)

• Diverge 3 (Looks great. Might buy one. Ergo-dox really has too many thumb keys anyway. This might be a better design.)

• Diverge TM 2 (Cool idea. Magnets! Too few keys for me.)

• Keyboardio (Halves can optionally be separated. Looks promising, but too few keys)

• Dygma Raise (Nice thumb keys layout, but no arrow keys and probably too big/unweildy for effective tenting)

• UltraErgo (Does not appear to be mechanical)

• Ultimate Hacking Keyboard (Small layout, mech switches, intersting-looking thumb attachments but missing arrow keys! And Kinda ungly)

• Lets Split (Dunno what this is yet)

• Mistel Barocco (no arrow keys, but looks good if you like 60% keyboards)

• Goldtouch (Technically one-piece, but close enough. I've used these. They're crap.)

• Goldtouch Go (Technically one-piece, but close enough. These are also crap.)

• Comfort Keyboard Split Magic Keyboard (This looks terrible)

• SafeType Keyboard (Also looks terrible)

• Axios (Something gloriously weird that is under development. Maybe.)

• Cheap Split PCB Boards for sale (Totally DIY. Soldering required!)

How long did it take you to get used to the ortholinear key layout on the ErgoDox?

I've got a Matias Ergo Pro. It is pretty nice, but in over a year of use I've got several sticky keys. I have other non split mechanical keyboards from steel series so I know there are better switches out there. Plus the keyboard is missing some important keys. Like insert for example.

You're missing a couple good ones:
https://gaming.kinesis-ergo.com/fsedge/ - Kinese Freestyle Edge - Freestyle 2 w/ mechanical keys and programmable layers
https://ultimatehackingkeyboard.com - programmable mechanical

This one looks interesting too: https://www.indiegogo.com/projects/dygma-raise-world-s-most-advanced-gaming-keyboard#/

Keeb.io makes a few different PCB's for splits

Kinesis Advantage, Kinesis Maxim Combo and Maltron dual-handed might count.

Freestyle Pro was released by Kinesis recently: https://www.kinesis-ergo.com/shop/freestyle-pro/.

It looks very similar to Freestyle Edge, but is a bit cheaper, and comes with no wrist rests.

Maybe this one? https://www.amazon.com/Koolertron-Programmable-Mechanical-Keyboard-Ergonomic/dp/B076FTKD6F/

Don't waste your time with the Matias Ergo Pros ... they are wonderful hardware with HORRIBLE firmware. I've owned 4 of them and every one has had different firmware issues from ghosting to phantom keypresses to caps lock lights randomly coming on (and staying on even when caps lock is not engaged), etc. I just sent back 2 of the new "soft touch" ones. The keys themselves are great, if they can ever get their firmware issues sorted out.

this one is pretty cheap and beautiful, not sure about the quality though.
https://item.taobao.com/item.htm?spm=a230r.1.14.29.68d16222La6Gri&id=556970472669&ns=1&abbucket=4#detail

Thanks for this list! This is out of stock but this is exactly what I'm looking for:

https://keeb.io/collections/frontpage/products/quefrency-60-split-staggered-keyboard?variant=12204552880222

A whole family of wireless splits I worked on https://github.com/joric/bluetosis (see end of README). Split keyboards are generally bad, your old typing habits become pretty much nil and you need different muscle memory for every possible distance between keyboard halves.

been using matias ergo pro for about a year now (avg ~3 days a week) and i definitely have a number of keys that are ghosting/jammed up. i don't recommend it.

Thanks for the good list. Are there any non-split ergo mechanical keyboards? If not, is there some physical limitation as to why that can't be? Thanks.

The ultimate hacking keyboard doesn't have dedicated arrow keys, but it has them on another layer that is super quick to access. I'd argue that it's better than dedicated arrow keys because you can keep your hands in their normal place to use them.

Thanks for the good list. Are there any non-split ergo mechanical keyboards? If not, is there some physical limitation as to why that can't be? Thanks.

X-bows is the only one I can find, though why not go split?

@itod I'm glad that according to the list, the UHK is ungly, not ugly. The latter would be a shocker. In case you meant the former, would you explain what makes it ugly? Disclaimer: I'm the founder of the UHK. See UHK pictures at https://ultimatehackingkeyboard.com/ for reference.

Thanks for the list! Seconding the addition of keeb.io - I like the Iris

@mondalaci I'm not the author but here are some of the reasons why I did not buy a UHK.

1. Inefficient use of top space

The slanted top increases the maximum height of the keyboard. This means the bounding box of the keyboard is made larger. This e.g. has implications for putting the keyboard into a backpack.
This increase in height would have been ok if it was not slanted. The slant reduces the amount of usable space from the top - especially towards the right and left edges - even though the bounding box is bigger. Inefficient.

Besides the above. The overall shapes in the keyboard are very rectangular. The slant breaks away from your own design pattern.

2. The display/status indicators.

The top display is rather basic in its capabilities yet it takes up a significant amount of space.
The status icons are in my opinion too big and the icon style feels "fat". I subjectively do not like it.
The 14-segment display is too big in my opinion relative to what it offers.

Removing the slant, making the top fully rectangular would allow you to utilize your space more efficiently (bounding box).
You could then potentially fit in a display on the top. This display would not only fulfill the function of the status indicators - but with easy modding support - it could be used for anything (it seems like you are targeting a niche technical market with your keyboard).

Or maybe removing the top part could be an option (other keyboards do this). You have cables sticking out vertically either way so the small form factor might be better. The status indicators could be replaced by labelled RGB LEDs.

3. Inefficient use of key space

This is a split keyboard - People who buy split keyboards probably type in a relatively structured way and want to type even more ergonomically/efficiently. One of the biggest selling points (for me at least) is the easy remapping and layers the keyboard offers. The purpose of this is (in my opinion) to increase the amount of easily accessible symbols/functions a user can access (The following is based on the ISO UHK).
I absolutely adore your work on the left half of the keyboard. Especially the splitting of keys you have made on the bottom-most row.
The right half is where the issues begin to arise. Our fingertips are relatively small, they do not need much space on a key for the key to be easily usable. The Ctrl key on the right half is huge. This comes at the cost of the removal of the Apps Key. The same could be said for the Shift key right above. I am going to guess that most people hit the Right Shift key on the left-most side. Splitting Shift into two keys, and then letting the left-most key be Shift would give us one extra key.
I dislike your choice of choosing to use the ANSI style enter key on the right hand side. I have been following UHK since the very beginning so I know your reasons. I will present why I dislike the choice.
I prefer the ISO layout because the amount of keys that are within quick reach is larger than the ANSI layout. You get the ISO key on the left hand side, and on the right hand side, you get one extra easily reachable key on the home row. The ANSI layout pushes this "home row" key away and up. My little finger is no longer able to reach the key in its new position without a hand movement - That's one less easily accessible key. I know key caps of arbitrary sizes might be hard to source, but at $350 for a keyboard... a solution should exist.

You might argue that few use the Apps Key and the previously mentioned key that would be pushed up and away by the ANSI style Enter.
I agree. But the UHK is a fully remappable keyboard - What the keys were before does not matter. The only thing that matters (in my opinion) is whether the keys are easily reachable, since any key can be anything.

In my case, I heavily rely on the "home row" key that has been displaced by the ANSI enter - Yes, I use it more than Enter in my work.

Ending remarks

I like your keyboard - so many good small thoughts have been put into it - I especially like the left hand side (especially the bottom-most row). Hopefully the next version (maybe even with a columnar layout?) will be it for me.

I hope my thoughts answered your question - even though the question wasn't meant for me.

The let's split is awesome and is my daily driver. Its an ortholiniar 40% that's programmed using the QMK software. It's a DIY keyboard that can be found on keeb.io going by the Levnison name. It does take some getting used to as it's a 40%, but since it uses QMK, it's very versatile.

@sarphiv Thanks for sharing your opinion! I appreciate it.

The use of top space may be inefficient, but the use of depth is more efficient than for any other keyboard which utilizes MX switches. The UHK is unusually thin for a mechanical keyboard, and we've put great effort into its design it as such. One cannot design a keyboard with efficient space utilization in every dimension, so a tradeoff must be made. Given how thin the UHK is, it may fit better in a backpack than other 60% keyboards depending on the available space.

The display doesn't take up any extra space. The space would have been used anyways for the 4P4C connectors of the bridge cable. 4P4C is the most robust connector I can think of, phone cables are retractable, various lenghts of cables are readily available, and they don't come apart by accident. Form follows function is one of our guiding design principles.

It will be possible to make the display show arbitrary content as you suggest.

As for the shape, it largely depends on whether the UHK is split or merged. Almost everyone uses it split which makes the top edges parallel in which case it looks much better than when merged. Given this reason, I don't think it'd have made sense to kill the top slant and take up more space at the top just to make the shape rectangular.

Small correction: the UHK costs $275, not 350. If you're an individual from the EU than it's definitely higher due to the Hungarian VAT. You should purchase it as a company if possible to avoid the VAT.

I personally disagree about the layout, but I understand your preferences and respect them. We'll release further UHKs of different layouts eventually. Feel free to subscribe to the monthly UHK newsletter, so that we can keep you in the loop.