This is an ESP8266 based dev board. This unit specifically uses the  ESP-12E module. NodeMCU is a an eLua based firmware for the ESP8266 however this module can also be programmed directly from the Arduino IDE.

NodeMCU Documentation
NodeMCU GitHub

Getting Started using the Arduino IDE

Please note that the USB-Serial converter is CH340 based. The drivers can be downloaded here:

• Windows
• Linux
• Mac