CatBoard - The first custom keyboard project, made in Russia by HABR user @ibnteo back in 2013.
Catboard v1:

Catboard ][ (v2):


It was one of the first fully developed projects, the features of this keyboard are:
Non-standard hardware layout with standard keyboard shortcuts; fast key repeat; Fn layer with cursor control keys, numpad, and function keys; separate keys for switching layouts; more convenient placement of Ctrl and Shift; dedicated AltTab key; Mac compatibility mode, allowing it to work exactly as on a PC; the ability to flash firmware without additional equipment; the ability to install over a laptop keyboard.
Its a really great project for its time, the one that started to explore ergonomics in cyrillic layout. It had 2 versions, CatBoard and CatBoard ][, Its also fully open-source, and you still can make one! As the inspiration for this project, were NSK 535 R and (of course) Kinesis. The author was dissapointed in modern keyboards in terms of ergonomics, NSK was considered one of the best ergo solutions by author, but unfortunately it couldnt be used with cyrillic.

After development of CardBoard v1, author found out the famous
ErgoDox, after which he started to work on v2 of CatBoard.

Also i found this. First sketch-up of Ergo layout, made by same person back in 2011, layout is called "Klavarog"

Development of CatBoard started back in 2005, but active stage was around 2010. First, Author started to work with POS keyboards, he bought cash register keyboard KBM-105, after finishing the layout - case development started, it was made in FabLab77 (IT openspace) and was based around AVR-USB162 controller.

Later, second iteration started being made.



HABR user @suenot builds white version of CatBoard ][.

CatBoard layout:

source:
https://habr.com/ru/articles/185500/