« Reply #1 on: April 06, 2018, 02:37:04 pm »
Depends exactly what you mean by 'internally'.
Plugin extensions are written in the Lua language, which itself is written in standard C (so hugely portable.) No doubt that portions of the MiOS system itself are in C and C++.

Logged
3x Vera Lite-UI5/Edge-UI7, 25x Fibaro, 23x TKB, 9x MiniMote, 2x NorthQ Power, 2x Netatmo, 1x Foscam FI9831P, 2x Philips Hue
Razberry, MySensors Arduino, HomeWave, AltUI, DataYours, openLuup, ZWay, ZeroBrane Studio.