D-duino is a combination of ESP8266 and OLED. You can use different language(Arduino&LUA) to program it.
Arduino core for ESP8266 WiFi chip https://github.com/lspoplove/Arduino
NodeMCU https://github.com/lspoplove/nodemcu-firmware
ESPRESSIF（AT command） http://espressif.com/en/support/explore/get-started/esp8266/getting-started-guide
D-duino V1 https://www.tindie.com/products/lspoplove/d-duino-esp8266-and-nodemcu-and-096-oled-display-/ https://www.elecrow.com/d-duino.html
D-duino V2 https://www.tindie.com/products/lspoplove/d-duino-v2arduino-and-nodemcu-and-esp8266-and-096oled/
D-duino-B https://www.tindie.com/products/lspoplove/d-duino-barduino-and-nodemcu-and-esp8266-and-13oled/