The ExtraDox is a split keyboard based off the ErgoDox, designed by Philippe Daouadi aka blastrock.
I improved on my previous design, here is the ExtraDox v2! Same as before, one extra row compared to the ErgoDox, Choc switches (Pro Red this time), MBK key caps (with some color) – blastrock0.
Compared to the original ErgoDox design, it has a function row, and it's designed for low-profile Choc switches. Compared to the ExtraDox v1, it has on-board controllers instead of Pro Micros, and the overall footprint of the case/PCB is smaller too.
The design is a little bit smaller and the only things that stick out of the cases are the TRRS sockets. It doesn't need a controller board as the controller (ATmega32u4) and the IO expander are soldered directly on the main boards, this makes for a thinner design – blastrock0.