Some thoughts about split keyboards.
In the last 5 or so years, mechanical keyboards have exploded in popularity. The last time I researched the topic, there were Cherry and Topre keys for hobbyists to buy, and an assortment of keycaps. There were a few open source keyboard firmware projects and hobbyists were starting to base their designs on them. Now there are dozens of key manufacturers, Cherry MX compatible for the most part, and a seemingly endless variety of keycaps and other assorted hardware. There are multiple firmware projects in different programming languages, CAD designs for nearly every aspect, and a bustling marketplace of hobbyists and custom builders.
It's been a fun transformation to witness.
The ergonomic keyboards I remember included the commercial Kinesis and the semi-hobbyist, semi-commercial (at the time) Ergodox. Some years back I purchased a Kinesis Freestyle, which is essentially a standard USB keyboard but split in half, with a wire connecting the two halves. It's not bad, but some minor complaints I have about it are the lack of tenting and the cables getting in the way. Also it seems unnecessarily large, perhaps because of the F-keys and extra keys on the outside edges of each half. The membrane keyswitches don't really bother me that much, perhaps because I am used to laptop keyboards.
Today, I noticed Kinesis has a new model, with mechanical keys and fully wireless. These are the features I want! Beyond the Kinesis, moergo has a split/tented/wireless keyboard called Glove80 (reviewed here) with even more features than the Kinesis. It's a good day for people like me with esoteric tastes in keyboards.