Despite having a look similar to many other ergo monoblock angled keyboards the Zephirum has a couple of unique features:
It has been designed with LibrePCB. The author thinks this EDA tool deserves more love so he published the project & library files.
Its MCU board is a Nucleo STM32WB55CG USB dongle (MB1293); it is surface mounted on the top to showcase it. ;)
Regarding the other features, they are more classic: Kailh Choc switches with MBK keycaps (L=17.5mm × H=16.5mm); powered by ZMK; only USB HID is supported so far; featuring an I²C 128x32 OLED screen (SSD1306).
I've never published my builds before, but it turns out I'm now motivated by the excellent dovenyi's Keyboard Builders' Digests ^_^' – cdc_mkb.
Oh, man, it's quite heartwarming to hear that. Thanks.