BlueMicro - A Keyboard Firmware for nRF52832 Boards with a pinout compatible with the Arduino Pro Micro.
Bluetosis - Bluetooth firmware for the Mitosis keyboard.
Lotlab/nrf52-keyboard - TMK based keyboard firmware for nRF52 series, now support both nRF52810 and nRF52832.
Lotlab/nrf51822-keyboard - This is a firmware based on nrf51822 Bluetooth keyboard, which uses nRF SDK 10.0 as the underlying hardware driver, and uses TMK keyboard library as the upper part of the keyboard function.
T-vK/ESP32-BLE-Keyboard - This library allows you to make the ESP32 act as a Bluetooth Keyboard and control what it does.
MK32 - BLE keyboard firmware for ESP32 microcontrollers,designed to be relativley easily customizable.
Key To Key - Rust libary for building keyboard firmwares.
Anne Key - Firmware for Anne Pro Keyboard written in Rust.